Microchannel reactors and fabrication processes

ABSTRACT

A microchannel reactor comprising: (a) a plurality of process microchannels having particulates packed along the length of the microchannels; (b) a plurality of heat transfer microchannels in thermal communication with the plurality of process microchannels; and, (c) a first retainer positioned at a first end of the plurality of process microchannels to inhibit the particulates from exiting the process microchannels via the first end.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the benefit of U.S. Provisional PatentApplication Ser. No. 61/509,469, entitled, “MICROCHANNEL REACTORS ANDFABRICATION PROCESSES,” filed Jul. 19, 2011, the disclosure of which ishereby incorporated by reference.

INTRODUCTION TO THE INVENTION

The present disclosure is directed to conducting chemical processingapplications in by manifolding streams to and from multiple parallelreactor modules and, more specifically, to conducting processing inmultiple reactor modules within pressure containing assemblies whichhave been designed to facilitate maintenance, repair, and replacement ofpacked beds of solid materials. The present disclosure includes methodsand devices particularly useful for construction and operation ofmultiple parallel chemical processing modules, each module comprisingmultiple distinct and separate process channels, such as microchannels,where each channel comprising packed beds of solids. The packed bed ofsolids may comprise one or more materials useful as a catalyst, sorbent,heat transfer material, mass transfer material, fluid distributionpacking, diluent, as a physical retention material for any of these, orany combination of these. The packed bed of solids may contain multipletypes of the foregoing materials. The types of chemical processingoperations supported by this invention include heterogeneously-catalyzedchemical reactions, adsorption, including temperature-swing adsorptionor pressure-swing adsorption, and separations, including absorption, anddistillation.

The catalyst may comprise any catalyst that is suitable for use inchemical reactors involving the use of fluid reactants. The catalyst maybe a catalyst useful in conducting one or more of the following chemicalreactions: acetylation addition, alkylation, dealkylation,hydrodealkylation, reductive alkylation, amination, ammonia synthesis,aromatization, arylation, autothermal reforming, carbonylation,decarbonylation, reductive carbonylation, carboxylation, reductivecarboxylation, reductive coupling, condensation, cracking,hydrocracking, cyclization, cyclooligomerization, ammoxidation,water-gas shift, dehalogenation, dimerization, epoxidation,esterification, Fischer-Tropsch reaction, halogenation,hydrohalogenation, homologation, hydration, dehydration, hydrogenation,dehydrogenation, hydrocarboxylation, hydroformylation, hydrogenolysis,hydrometallation, hydrosilation, hydrolysis, hydrotreating,isomerization, methylation, demethylation, metathesis, methanolsynthesis, nitration, oxidation, partial oxidation, polymerization,reduction, reformation, reverse water gas shift, sulfonation,telomerization, transesterification, trimerization, Sabatier reaction,carbon dioxide reforming, preferential oxidation, or preferentialmethanation.

The catalyst may comprise a metal, metal oxide or mixed metal oxide of ametal selected from Mo, W, V, Nb, Sb, Sn, Pt, Pd, Cs, Zr, Cr, Mg, Mn,Ni, Co, Ce, or a mixture of two or more thereof. These catalysts mayalso comprise one or more alkali metals or alkaline earth metals orother transition metals, rare earth metals, or lanthanides. Additionallyelements such as P and Bi may be present.

The catalyst may comprise one or more: catalyst metals, including noblemetals, transition metals and combinations thereof; metal oxides,including oxides of alkali metals, alkaline earth metals, boron,gallium, germanium, arsenic, selenium, tellurium, thallium, lead,bismuth, polonium, magnesium, titanium, vanadium, chromium, manganese,iron, nickel, cobalt, copper, zinc, zirconium, molybdenum, tin, calcium,aluminum, silicon, lanthanum series element (s), and combinationsthereof; composites; zeolite (s); nitrides; carbides; sulfides; halides;phosphates; and combinations of any of the above.

The sorption medium may be inorganic. Examples of inorganic sorptionmediums that may be used include Sb₂O₅, AgO, PtO, CrO₂, PbO, HgO, Cu₂O,MnO, Mn₂O₃, Bi₂O₄, NiO, NiO₂, Cu₂O₃, SnO, SnO₂, WO₂, WO₃, W₂O₅,perfluorinated film, Pt/γ-alumina, Fe/γ-alumina, Cu/γ-alumina,Zn/γ-alumina, Co/γ-alumina, zeolite, or a combination of two or morethereof. Included in this group are metal cyanide oligomers andpolymers. These include the oligomers and polymers represented by theformulae [Cu(I)(CN)_(x)]_(n), [Fe(II)(CN)_(y)]_(n), or[Co(II)(CN)_(y)]_(n), wherein x is 3; y is 5; and n is a number that isat least 2, and in one embodiment is in the range of about 2 to about16,500, and in one embodiment about 1000 to about 10,000.

The sorption medium may comprise silver, gold, platinum, copper, zinc,palladium, nickel, zeolite, silica gel, carbon molecular sieves,polymeric materials, alumina, inorganic complexes (e.g., metal centeredporphyrin rings) or a combination of two or more thereof.

In one embodiment, the sorption medium comprises a reactive complexationsorbent that forms a reversible chemical complex with a fluid componentat a relatively high temperature wherein the fluid component is sorbedby the surface of the sorption medium. At a lower temperature thechemical reaction is reversed and the complexed fluid is recovered in amore purified form.

The sorption medium may comprise an antioxidant. Examples includesecondary amines, phenolic phosphates, phosphites, phenolics,bisphenolics, hydroxylamines, olefinic carboxylates, amino carboxylates(e.g., ethylene diamine tetracetic acid and salts thereof), tocopherol,di-tertiarybutyl-p-cresol, stannous salts, stannous oxides, sorbate,polysorbate, or a combination of two or more thereof.

As disclosed herein, the exemplary microchannel devices may be utilizedto carry out a Fisher-Tropsch (FT) process and more broadly on any highpressure (defined as an operating pressure greater than 2 bar) reactionsystem. The FT process was first developed by Franz Fischer and HanzTropsch in Germany in the 1920s and 1930s. The chemistry is based onmaking longer chain hydrocarbons from a mixture of carbon monoxide (CO)and hydrogen (H2), referred to as “synthesis gas”, at an elevatedpressure and temperature and in the presence of a catalyst. The FTreaction may be carried out in a chemical reactor containing a fixed bedof solid catalyst. Suitable FT catalyst compositions are known in theart. The excess heat generated from conducting the FT reaction in afixed catalyst bed has typically been removed by inserting boiler tubesthat carry water. In theory, any source of carbon can be used togenerate the synthesis gas.

The majority of the products from FT synthesis are paraffinic waxesbased on the following chemical equation.

nCO+(2n+1)H₂→C_(n)H_(2n+2)+H₂O  (1)

Typical byproducts are liquefied petroleum gas (LPG) and naphtha. Afterthe FT process, heavier hydrocarbons can be hydrocracked to producedistillate products, notably diesel and jet fuels. FT derivedtransportation fuels are typically referred to as synthetic fuels.

Conventional microchannel technology typically uses diffusion bondingand/or brazing to secure large area metal shim layers to one another. Itis believed that without bonding the entire exposed surfaces of the shimlayers to one another, the microchannel device will not withstand normalor elevated operating pressures. At the same time, conventional wisdomgreatly favors diffusion bonding and/or brazing to ensure parallelmicrochannels are not in communication with one another (i.e., completechannel separation even between channels carrying the same contents).Diffusion bonding and brazing rely on the formation of a contiguousmetallic interface between the microchannel layers. The contiguousinterface is thought to be advantageous for the purposes of heattransfer from one microchannel to an adjacent microchannel and to avoidcross-talk of fluids which may create an operational challenge wherebyboiling in the coolant channels could lead to local dryout if flow couldmove away from high flux zones.

Brazing is the process to bond two objects to one another that reliesupon the addition of an interlayer material that melts at a temperaturebelow the melting temperature of the materials to be bonded. Theinterlayer material becomes liquid during the diffusion brazing orbrazing process and flows to fill any gaps or voids between thematerials to be joined. As the interlayer material cools, it solidifiesto joint the adjacent materials. But when the interlayer material isliquefied, it may also diffuse into the materials to be joined.Likewise, the materials to be joined may diffuse into the interlayermaterial. As diffusion progresses, the local composition of theinterlayer material may significantly change.

The inventors of the subject matter disclosed herein have defiedconventional wisdom and created microchannel technology that does notrely on diffusion bonding and/or brazing to secure microchannel shimlayers to one another. Instead, the novel microchannel technologydisclosed herein makes use of welding to secure the shim layers to oneanother. By using welding instead of brazing or diffusion bonding, theprocess costs are significantly reduced and manufacturing scale-up tolarge hardware is considerably easier as induced thermal deformationfrom bonding and brazing of large devices is avoided.

Welded microchannel reactors which operate with fluids at differentialpressures more than about 2 bar, such as 4 to 100 bar (or morespecifically within the range of 5 to 40 bar) from ambient pressurerequire external support into order to maintain mechanical integrity.These external supports may include compression reactor assemblies, asexemplified in US2005/0249647, which is incorporated by reference. Theseexternal supports may also include external mechanical structuralsupports as exemplified in U.S. patent application Ser. Nos. 61/394,328filed Oct. 18, 2010 and 61/441,276 filed Feb. 9, 2011, which areincorporated by reference. Additional designs for providing support towelded reactors are provided in the following description.

The exemplary pressure containment systems differs from the prior artthrough a reduction in the amount of metal required to contain apressurized microchannel device when the device is not internally joinedas with bonding or brazing. In the prior art, a pressurized shell with asingle pressurized fluid surrounded four or more sides of a microchanneldevice. The exemplary devices described herein require less metal tocontain pressure within the devices. In exemplary form, pressurizedzones, such as cylindrical or curved, are placed around two faces of thedevice that do not contain inlet or outlet flow streams. On faces whichinclude flow streams, the pressure is contained in headers and footerswithout secondary pressure containment.

One of the problems addressed by the exemplary embodiments is reducingthe amount of material and thus cost to contain high pressure fluids inwelded microchannel reactors that are not internally sealed, such as byusing bonding or brazing. The solution, in part, may include containinghigh internal pressures using higher pressure external fluids inselective locations of the device or through the use of thick (greaterthan 3 cm, or in a range of 3 to 50 cm (such as 3 to 15 cm)) endplateswithout the use of a secondary fluid. Both solutions require less metaland thus are lower cost than the use of a high pressure fluidsurrounding the entire device which includes four or more faces.

Additional problems addressed by the exemplary embodiments are: (a) theneed to load solid particulate materials into multiple parallel andseparate microchannels contained within a pressure vessel withsufficient uniformity to achieve desired packing density, without whichthe chemical processor may not achieve desired performance; (b) the needto provide a precise, repeatable catalyst loading process for multipleparallel and separate microchannels contained within a pressure vessel,(b) the need to need to unload solid particulate materials from multipleparallel microchannels contained within a pressure vessel in order torefresh the chemical processor with new materials; (c) the need toprovide loading and unloading of solid materials using a densificationapparatus that is placed within a pressure vessel and which enablesloading of multiple parallel microchannels with sufficient uniformity;and, (d) the need to provide service to chemical processors located inthe field at a plant or in a remote location by using a portabledensification apparatus that is placed within a pressure vessel andwhich enables loading of solid materials with sufficient uniformity intomultiple parallel microchannels contained within said pressure vessel.For example, when a catalyst has reached its useful life in service anda plant owner schedules a change out of the used catalyst for freshcatalyst, a catalyst handling service provider may use the portabledensification apparatus to provide catalyst unloading and loadingservices to the reactor owner. These and other exemplary advantagesshould be apparent to those skilled in the art after reviewing thefollowing description of exemplary embodiments.

In a first aspect, the invention provides a method of increasing packingdensity of particulates loaded into a plurality of microchannels inmicrochannel apparatus, comprising: providing a microchannel apparatuscomprising a plurality of microchannels that comprise particulates;positioning a ultrasound-producing head at one end of the plurality ofmicrochannels and placing the head in sonic contact with the pluralityof microchannels; and, applying ultrasonic energy to the plurality ofmicrochannels from the ultrasound-producing head. In some preferredembodiments, the invention can be further characterized by one or anycombination of the following characteristics: a sonically conductivematerial is disposed between the ultrasound-producing head and theplurality of microchannels; the ultrasonic energy has a frequency of 15to 40 kHz; wherein the ultrasound-producing head is pressed against theapparatus with a contact pressure of 100 kPa (15 psi) to 280 kPa (40psi); wherein the ultrasonic energy is provided in bursts of 30 secondsor less, more preferably from 1 to 10 seconds, and in some embodimentsin that range of 1 to 5 seconds; wherein each microchannel in theplurality of microchannels has a length of at least 10 cm and at leastone dimension of 10 mm or less; wherein the microchannel apparatuscomprises at least 1000 microchannels and wherein theultrasound-producing head extends over no more than 500 of said at least1000 microchannels at one time; wherein the microchannel apparatuscomprises an insert that extends down the length of the microchannel;wherein the insert transmits sonic energy down the length of themicrochannel; wherein the microchannel apparatus comprises channels atleast partly defined by walls of a wave-shaped insert (an example of theconstruction of a waveform is shown in FIG. 9); wherein the microchannelapparatus comprises plural inserts that extend down the length of theplurality of microchannels; wherein the inserts transmit sonic energydown the length of the plurality of microchannels; further comprising astep, that is subsequent to the step of applying ultrasonic energy, ofattaching a manifold that covers the ends of the plurality ofmicrochannels and creates a flow path for fluid into or out of theplurality of microchannels. In some preferred embodiments, themicrochannel is defined by a first wall and a second wall and the inserthas lower mass than either the first or second walls, typically athickness that is 50% or less than the thickness of either the first orthe second walls. Insert can have shapes such as a waveform, or aspiral. The term “extends down the length” means that the insert has alength that is in the same direction as the length of the microchannels.The microchannel length is typically longer than the insert length. Inpreferred embodiments, the insert's length is at least 50% that of themicrochannel, in some embodiments, at least 90% of the microchannel'slength.

In a second aspect, the invention provides a method of unloadingparticulates from microchannel apparatus, comprising: providing amicrochannel apparatus comprising a plurality of microchannels thatcomprise particulates; positioning a ultrasound-producing head at oneend of the plurality of microchannels and placing the head in soniccontact with the plurality of microchannels; and, applying ultrasonicenergy to the plurality of microchannels from the ultrasound-producinghead; wherein the step of applying ultrasonic energy is conducted whilethe plurality of microchannels are dry (note that “dry” means that thechannels comprise a greater volume of gas than volume of liquid).

It is a third aspect of the present invention to provide a method ofloading material within a microchannel device, the method comprising:(a) loading particulates into a plurality of microchannels; and, (b)ultrasonically packing the particulates into the plurality ofmicrochannels using a portable, compact ultrasonic densification unit.

In a more detailed embodiment of the third aspect, the act of loadingparticulates into the plurality of microchannels creates a microchannelpacked bed. In yet another more detailed embodiment, the plurality ofmicrochannels are arranged in parallel to one another. In a furtherdetailed embodiment, the particulates comprise at least one of acatalyst, a sorbent, a heat transfer material, a mass transfer material,a fluid distribution packing, and a diluent. In still a further detailedembodiment, the particulates comprise a catalyst. In a more detailedembodiment, the method further includes dislodging used particulatesfrom the plurality of microchannels, where the used particulates waspacked within the plurality of microchannels. In a more detailedembodiment, the method further includes removing a first barrierdownstream from the plurality of microchannels prior to dislodging spentcatalyst from the plurality of microchannels, the first barrierinhibiting catalyst housed within the plurality of microchannels frompassing therethrough, and reinstalling the first barrier downstream fromthe plurality of microchannels prior to loading the particulates intothe plurality of microchannels. In another more detailed embodiment, themethod further includes removing a first barrier downstream from theplurality of microchannels prior to dislodging spent catalyst from theplurality of microchannels, the first barrier inhibiting catalyst housedwithin the plurality of microchannels from passing therethrough, andinstalling a second barrier downstream from the plurality ofmicrochannels prior to loading the particulates into the plurality ofmicrochannels, the second barrier inhibiting catalyst housed within theplurality of microchannels from passing therethrough. In yet anothermore detailed embodiment, the method further includes removing a thirdbarrier upstream from the plurality of microchannels prior to dislodgingspent catalyst from the plurality of microchannels, the third barrierinhibiting catalyst housed within the plurality of microchannels frompassing therethrough, and installing a fourth barrier upstream from theplurality of microchannels subsequent to ultrasonically packing theparticulates into the plurality of microchannels, the fourth barrierinhibiting catalyst housed within the plurality of microchannels frompassing therethrough. In still another more detailed embodiment, theplurality of microchannels extend in parallel to one another, each ofthe plurality of microchannels includes a linear segment, the linearsegment houses at least one of the spent catalyst and the particulates,and ultrasonically packing the particulates into the plurality ofmicrochannels includes increasing the density of particulates between 1grams per milliliter to 1.5 grams per milliliter.

In yet another more detailed embodiment of the third aspect, theplurality of microchannels are arranged in multiple layers, where atleast two of the layers are spaced apart from one another, and the stepof ultrasonically packing the particulates into the plurality ofmicrochannels includes packing certain layers prior to other layers. Instill another more detailed embodiment, at least two of the multiplelayers of the plurality of microchannels are spaced apart from oneanother by a layer of intervening channels. In a further detailedembodiment, the intervening channels comprise coolant channels and thecoolant channels comprise coolant microchannels. In still a furtherdetailed embodiment, the portable, compact ultrasonic densification unitincludes a programmable ultrasonic packer, the step of ultrasonicallypacking the particulates into the plurality of microchannels includesusing the programmable ultrasonic packer, and the programmableultrasonic packer is autonomously repositionable with respect to theplurality of microchannels. In a more detailed embodiment, the portable,compact ultrasonic densification unit includes an ultrasonic packer, thestep of ultrasonically packing the particulates into the plurality ofmicrochannels includes using the ultrasonic packer, and the ultrasonicpacker is manually repositionable with respect to the plurality ofmicrochannels. In a more detailed embodiment, the method furtherincludes installing a first barrier downstream from the plurality ofmicrochannels prior to loading the particulates into the plurality ofmicrochannels, the first barrier inhibiting catalyst housed within theplurality of microchannels from passing therethrough. In another moredetailed embodiment, the method further includes installing a secondbarrier upstream from the plurality of microchannels subsequent toultrasonically packing the particulates into the plurality ofmicrochannels, the second barrier inhibiting catalyst housed within theplurality of microchannels from passing therethrough. In yet anothermore detailed embodiment, the act of loading particulates into theplurality of microchannels includes distributing particulateparticulates into the plurality of microchannels.

In a more detailed embodiment of the third aspect, the act ofultrasonically packing the particulates includes verticallyrepositioning an ultrasonic horn to contact a first set of a pluralityof coolant microchannels adjacent the plurality of microchannels, andactivating the ultrasonic horn after contacting the first set of theplurality of coolant microchannels. In yet another more detailedembodiment, the ultrasonic horn emanates sound waves having a frequencybetween twenty to forty kilohertz. In a further detailed embodiment, theultrasonic horn is pressed against the first set of the plurality ofcoolant microchannel with a contact pressure of between 200 kilopascalsto 280 kilopascals. In still a further detailed embodiment, theultrasonic horn is activated in bursts of thirty seconds or less. In amore detailed embodiment, the ultrasonic horn is activated in bursts often seconds or less. In a more detailed embodiment, the ultrasonic hornis activated in bursts of three seconds or less. In another moredetailed embodiment, the act of ultrasonically packing the particulatesincludes vertically repositioning the ultrasonic horn to no longercontact the first set of the plurality of coolant microchannels,horizontally repositioning the ultrasonic horn, lowering the ultrasonichorn to contact a second set of the plurality of coolant microchannelsadjacent the plurality of microchannels, and activating the ultrasonichorn after contacting the second set of the plurality of coolantmicrochannels. In yet another more detailed embodiment, the methodfurther includes assembling the portable, compact ultrasonicdensification unit within a pressure vessel housing the plurality ofmicrochannels prior to the act of ultrasonically packing theparticulates, and disassembling the portable, compact ultrasonicdensification unit and removing the portable, compact ultrasonicdensification unit from the pressure vessel housing the plurality ofmicrochannels subsequent to the act of ultrasonically packing theparticulates. In still another more detailed embodiment, the methodfurther includes loading a second amount of particulates into aplurality of microchannels after initially ultrasonically packing theparticulates, and ultrasonically packing the second amount particulatesinto the plurality of microchannels using the portable, compactultrasonic densification unit.

It is a fourth aspect of the present invention to provide a portable,compact ultrasonic packer comprising a mobile carriage including anultrasonic horn, the mobile carriage traverses along a rail in order toreposition the mobile carriage horizontally, where the ultrasonic hornis vertically repositionable with respect to the rail, and where therail comprises at least two sections operatively coupled to one another.

In a more detailed embodiment of the fourth aspect, the rail comprises ahorizontal member. In yet another more detailed embodiment, the railcomprises a right side rail and a left side rail, the right side railcomprises a first section removably coupled to a second section, theleft side rail comprises a third section removably coupled to a fourthsection, and the mobile carriage spans between the right side rail andthe left side rail. In a further detailed embodiment, the first section,the second section, the third section, and the fourth section comprise aplanar, horizontal surface upon which the mobile carriage may berepositioned, and a vertical surface including a plurality of evenlyspaced orifices, and the mobile carriage includes a repositionableactuator that is configured to move between an extended position and aretracted position, the repositionable actuator sized so that at least aportion thereof can be received within at least one of the plurality ofevenly spaced orifices. In still a further detailed embodiment, themobile carriage includes a first wheel that rides upon at least one ofthe first and second sections, and a second wheel that rides upon atleast one of the third and fourth sections. In a more detailedembodiment, the rail includes a plurality of evenly spaced apartorifices distributed therealong, and the mobile carriage includes arepositionable actuator that is configured to move between an extendedposition and a retracted position, the repositionable actuator sized sothat at least a portion thereof can be received within at least one ofthe plurality of orifices of the rail. In a more detailed embodiment,the mobile carriage includes a wheel that rides upon the rail. Inanother more detailed embodiment, the ultrasonic horn is verticallyrepositionable with respect to the mobile carriage, and the ultrasonichorn comprises a first ultrasonic horn and a second ultrasonic horn. Inyet another more detailed embodiment, the ultrasonic horn ispneumatically repositionable with respect to the mobile carriage, andthe first ultrasonic horn is oriented on the left side of the carriageand the second ultrasonic horn is orientated on the right side of thecarriage. In still another more detailed embodiment, the portable,compact ultrasonic packer further comprises a microchannel apparatus,where the mobile carriage is repositionably mounted to the microchannelapparatus.

It is a fifth aspect of the present invention to provide a microchannelreactor comprising: (a) a plurality of reaction microchannels having aparticulate catalyst packed along the length of the microchannels; (b) aplurality of heat transfer microchannels in thermal communication withthe plurality of reaction microchannels; and, (c) a first retainerpositioned at a first end of the plurality of microchannels to inhibitthe particulate catalyst from exiting the reaction microchannels via thefirst end.

In a more detailed embodiment of the fifth aspect, the microchannelreactor further includes a second retainer positioned at a second end ofthe plurality of microchannels, opposite the first end, to inhibit theparticulate catalyst from exiting the reaction microchannels via thesecond end. In yet another more detailed embodiment, at least one of thefirst retainer and the second retainer includes a screen. In a furtherdetailed embodiment, the first retainer and the second retainer eachinclude the screen, and the screen is fabricated from at least one of ametal, a ceramic, stainless steel, a nickel alloy, a cobalt alloy, aniron alloy, copper, aluminum, a glass, and a plastic. In still a furtherdetailed embodiment, the first retainer comprises a screen fabricatedfrom at least one of a metal, a ceramic, stainless steel, a nickelalloy, a cobalt alloy, an iron alloy, copper, aluminum, a glass, and aplastic. In a more detailed embodiment, at least one of the firstretainer and the second retainer includes a porous foam. In a moredetailed embodiment, the first retainer and the second retainer eachinclude the porous foam, and the porous foam is fabricated from at leastone of a metal, a ceramic, stainless steel, a nickel alloy, a cobaltalloy, an iron alloy, copper, aluminum, a glass, and a plastic. Inanother more detailed embodiment, the first retainer comprises a porousfoam fabricated from at least one of a metal, a ceramic, stainlesssteel, a nickel alloy, a cobalt alloy, an iron alloy, copper, aluminum,a glass, and a plastic. In yet another more detailed embodiment, thefirst retainer includes a porous foam fabricated from at least one of ametal, a ceramic, stainless steel, a nickel alloy, a cobalt alloy, aniron alloy, copper, aluminum, a glass, and a plastic and a screenfabricated from at least one of a metal, a ceramic, stainless steel, anickel alloy, a cobalt alloy, an iron alloy, copper, aluminum, a glass,and a plastic. In still another more detailed embodiment, at least oneof the first retainer and the second retainer includes a screen and aporous foam.

In yet another more detailed embodiment of the fifth aspect, the firstretainer and the second retainer each include the screen and the porousfoam, the screen is fabricated from at least one of a metal, a ceramic,stainless steel, a nickel alloy, a cobalt alloy, an iron alloy, copper,aluminum, a glass, and a plastic, and the screen is fabricated from atleast one of a metal, a ceramic, stainless steel, a nickel alloy, acobalt alloy, an iron alloy, copper, aluminum, a glass, and a plastic.In still another more detailed embodiment, the first retainer isremovably mounted to the microchannel reactor via at least one of afriction fit and a mechanical fastener. In a further detailedembodiment, the friction fit is achieved by pinching the first retainerwithin a joint. In still a further detailed embodiment, the mechanicalfastener comprises a framework overlying the first retailer and aplurality of bolts. In a more detailed embodiment, each of the pluralityof bolts is received within a T-shaped channel formed within a supportof the microchannel reactor. In a more detailed embodiment, the firstretainer and the second retainer are removably mounted to themicrochannel reactor via at least one of a friction fit and a mechanicalfastener. In another more detailed embodiment, the plurality of reactionmicrochannels are distributed amongst a plurality of reaction layers,the plurality of heat transfer microchannels are distributed amongst aplurality of coolant layers, a first predetermined number of reactionlayers are interposed by a second predetermined number of coolant layersto comprise a sub-stack, and where the sub-stack includes a pair of endplates interposed by the reaction layers and coolant layers. In yetanother more detailed embodiment, a plurality of sub-stacks are placedadjacent one another and mounted to each other to comprise a core, thecore includes a top surface and a bottom surface angled ninety degreeswith respect to each of four sides comprising a reactant entrance side,a product exit side, a coolant inlet side, and a coolant outlet side,and the core includes a plurality of vertical flanges mounted thereto,the plurality of vertical flanges cooperating to form a reactantentrance halo on the reactant entrance side, a product exit halo on theproduct exit side, a coolant inlet halo on the coolant inlet side, and acoolant outlet halo on the coolant outlet side.

In a more detailed embodiment of the fifth aspect, the reactant entrancehalo is mounted to a first arcuate plate, the product exit halo ismounted to a second arcuate plate, the coolant entrance halo is mountedto a third arcuate plate, the coolant exit halo is mounted to a fourtharcuate plate, and the first, second, third, and fourth plates cooperateto circumferentially enclose the stacked structure. In yet another moredetailed embodiment, the first arcuate plate includes a reactantentrance orifice, the second arcuate plate includes a product exitorifice, the third arcuate plate includes a coolant entrance orifice,the fourth arcuate plate includes a coolant exit orifice, the first andsecond plates are opposite each other, the third and fourth plates areopposite each other, the third and fourth plates adjoin the first plate,and the third and fourth plates adjoin the second plate. In a furtherdetailed embodiment, the reactant entrance orifice is in fluidcommunication with the plurality of microchannels, but not in fluidcommunication with the plurality of coolant microchannels, and thecoolant entrance orifice is in fluid communication with the plurality ofcoolant microchannels, but not in fluid communication with the pluralityof microchannels. In still a further detailed embodiment, at least oneof the first and second plates includes a manway. In a more detailedembodiment, both of the first and second plates includes a manway.

It is a sixth aspect of the present invention to provide a microchannelreactor comprising: (a) a plurality of reaction microchannels havingcatalyst contained therein, each of the plurality of reactionmicrochannels having an entrance that is aligned along a reactantentrance side and each of the plurality of reaction microchannels havingan exit that is aligned along a product exit side; and, (b) a pluralityof heat transfer microchannels in thermal communication with theplurality of reaction microchannels, each of the plurality of heattransfer microchannels having an entrance that is aligned along acoolant entrance side and each of the plurality of heat transfermicrochannels having an exit that is aligned along a coolant exit side,where the reactant entrance side is angled at least forty-five degreesfrom the product exit side, and the coolant inlet side is angled atleast forty-five degrees from the coolant outlet side.

In a more detailed embodiment of the sixth aspect, the reactant entranceside includes a first cover to distribute fluid flow into the entranceof each of the plurality of reaction microchannels, the product exitside includes a second cover to consolidate fluid flow coming out of theexit of each of the plurality of reaction microchannels, the coolantentrance side includes a third cover to distribute fluid flow into theentrance of each of the plurality of coolant microchannels, the coolantexit side includes a fourth cover to consolidate fluid flow coming outof the exit of each of the plurality of coolant microchannels, and thefirst cover, the second cover, the third cover, and the fourth cover aremounted to one another to comprise a pressure vessel containing theplurality of reaction microchannels and the plurality of coolantmicrochannels. In yet another more detailed embodiment, at least two ofthe plurality of reactant microchannels is interposed by at least one ofthe plurality of coolant microchannels. In a further detailedembodiment, the plurality of reactant microchannels are divided into aplurality of discrete reactant layers having multiple reactantmicrochannels extending parallel to one another, the plurality ofcoolant microchannels are divided into a plurality of discrete coolantlayers having multiple coolant microchannels extending parallel to oneanother, and a stacked structure is formed by stacking in an alternatingpattern one of the discrete reactant layers with one of the discretecoolant layers to have a rectangular horizontal cross-section and arectangular vertical cross-section. In still a further detailedembodiment, the stacked structure includes four sides comprising thereactant entrance side, the product exit side, the coolant inlet side,and the coolant outlet side, the reactant entrance side is angled atleast ninety degrees from the product exit side, and the coolant inletside is angled at least ninety degrees from the coolant outlet side. Ina more detailed embodiment, the stacked structure includes a top surfaceand a bottom surface angled ninety degrees with respect to each of thefour sides, and the stacked structure includes a plurality of verticalflanges mounted thereto, the plurality of vertical flanges cooperatingto form a reactant entrance halo on the reactant entrance side, aproduct exit halo on the product exit side, a coolant inlet halo on thecoolant inlet side, and a coolant outlet halo on the coolant outletside. In a more detailed embodiment, the reactant entrance halo ismounted to a first arcuate plate, the product exit halo is mounted to asecond arcuate plate, the coolant entrance halo is mounted to a thirdarcuate plate, the coolant exit halo is mounted to a fourth arcuateplate, and the first, second, third, and fourth plates cooperate tocircumferentially enclose the stacked structure. In another moredetailed embodiment, the first arcuate plate includes a reactantentrance orifice, the second arcuate plate includes a product exitorifice, the third arcuate plate includes a coolant entrance orifice,the fourth arcuate plate includes a coolant exit orifice, the first andsecond plates are opposite each other, the third and fourth plates areopposite each other, the third and fourth plates adjoin the first plate,and the third and fourth plates adjoin the second plate. In yet anothermore detailed embodiment, the reactant entrance orifice is in fluidcommunication with the plurality of reactant microchannels, but not influid communication with the plurality of coolant microchannels, and thecoolant entrance orifice is in fluid communication with the plurality ofcoolant microchannels, but not in fluid communication with the pluralityof reactant microchannels. In still another more detailed embodiment, atleast one of the first and second plates includes a manway.

In yet another more detailed embodiment of the sixth aspect, both of thefirst and second plates includes a manway. In still another moredetailed embodiment, the microchannel reactor further comprises a firstretainer positioned at a first end of the plurality of microchannels toinhibit the particulate catalyst from exiting the reaction microchannelsvia the first end. In a further detailed embodiment, the microchannelreactor further comprises a second retainer positioned at a second endof the plurality of microchannels, opposite the first end, to inhibitthe particulate catalyst from exiting the reaction microchannels via thesecond end. In still a further detailed embodiment, at least one of thefirst retainer and the second retainer includes a screen. In a moredetailed embodiment, the first retainer and the second retainer eachinclude the screen, and the screen is fabricated from at least one of ametal, a ceramic, stainless steel, a nickel alloy, a cobalt alloy, aniron alloy, copper, aluminum, a glass, and a plastic. In a more detailedembodiment, the first retainer comprises a screen fabricated from atleast one of a metal, a ceramic, stainless steel, a nickel alloy, acobalt alloy, an iron alloy, copper, aluminum, a glass, and a plastic.In another more detailed embodiment, at least one of the first retainerand the second retainer includes a porous foam. In yet another moredetailed embodiment, the first retainer and the second retainer eachinclude the porous foam, and the porous foam is fabricated from at leastone of a metal, a ceramic, stainless steel, a nickel alloy, a cobaltalloy, an iron alloy, copper, aluminum, a glass, and a plastic.

In yet another more detailed embodiment of the sixth aspect, the firstretainer comprises a porous foam fabricated from at least one of ametal, a ceramic, stainless steel, a nickel alloy, a cobalt alloy, aniron alloy, copper, aluminum, a glass, and a plastic. In still anothermore detailed embodiment, the first retainer includes a porous foamfabricated from at least one of a metal, a ceramic, stainless steel, anickel alloy, a cobalt alloy, an iron alloy, copper, aluminum, a glass,and a plastic, and the first retainer includes a screen fabricated fromat least one of a metal, a ceramic, stainless steel, a nickel alloy, acobalt alloy, an iron alloy, copper, aluminum, a glass, and a plastic.In a further detailed embodiment, at least one of the first retainer andthe second retainer includes a screen and a porous foam. In still afurther detailed embodiment, the first retainer and the second retainereach include the screen and the porous foam, the screen is fabricatedfrom at least one of a metal, a ceramic, stainless steel, a nickelalloy, a cobalt alloy, an iron alloy, copper, aluminum, a glass, and aplastic, and the porous foam is fabricated from at least one of a metal,a ceramic, stainless steel, a nickel alloy, a cobalt alloy, an ironalloy, copper, aluminum, a glass, and a plastic. In a more detailedembodiment, the first retainer is removably mounted to the microchannelreactor via at least one of a friction fit and a mechanical fastener. Ina more detailed embodiment, the friction fit is achieved by pinching thefirst retainer within a joint. In another more detailed embodiment, themechanical fastener comprises a framework overlying the first retailerand a plurality of bolts. In yet another more detailed embodiment, eachof the plurality of bolts is received within a T-shaped channel formedwithin a support of the microchannel reactor.

It is a seventh aspect of the present invention to provide amicrochannel device comprising: (a) a plurality of process microchannelsdistributed circumferentially around a longitudinal axis, at least aportion of the reaction microchannels partially defined by a processlayer having a cross sectional area that increases as a distance fromthe longitudinal axis increases; and, (b) a plurality of heat transfermicrochannels circumferentially distributed around the longitudinal axisand in thermal communication with the plurality of reactionmicrochannels.

In a more detailed embodiment of the seventh aspect, the process layercomprises a waveform having a thickness that increases as the distancefrom the longitudinal axis increases to increase the cross sectionalarea. In yet another more detailed embodiment, the microchannel devicehas a circular horizontal cross-section. In a further detailedembodiment, the process layer comprises a waveform having an amplitudethat increases as the distance from the longitudinal axis increases toincrease the cross sectional area. In still a further detailedembodiment, the plurality of heat transfer microchannels are dividedinto discrete radial heat transfer wedges, and the plurality of processmicrochannels are divided into discrete radial process wedges. In a moredetailed embodiment, the discrete process reaction wedges have processmicrochannels that extend parallel to the longitudinal axis, ahorizontal cross-sectional area of the process microchannels increasesas the distance from the longitudinal axis increases, the discreteradial heat transfer wedges have heat transfer microchannels that extendperpendicular to the longitudinal axis, and a vertical cross-sectionalarea of the heat transfer microchannels increases as the distance fromthe longitudinal axis increases. In a more detailed embodiment, thediscrete radial process wedges circumferentially alternate with thediscrete radial heat transfer wedges. In another more detailedembodiment, the discrete radial process wedges have reactionmicrochannels that extend parallel to the longitudinal axis, ahorizontal cross-sectional area of the process microchannels increasesas the distance from the longitudinal axis increases, the discreteradial heat transfer wedges have heat transfer microchannels that extendparallel to the longitudinal axis, and where a horizontalcross-sectional area of the heat transfer microchannels increases as thedistance from the longitudinal axis increases. In yet another moredetailed embodiment, the discrete radial process wedgescircumferentially alternate with the discrete radial heat transferwedges. In still another more detailed embodiment, the waveform includesa constant overall length, and the waveform includes a constant overallwidth.

In yet another more detailed embodiment of the seventh aspect, themicrochannel device further includes a first process manifold having aring shape that is in fluid communication with the plurality of processmicrochannels. In still another more detailed embodiment, themicrochannel device further includes a second reaction manifold having aring shape that is in fluid communication with the plurality of processmicrochannels, where the plurality of process microchannels interposethe first process manifold and the second process manifold. In a furtherdetailed embodiment, the microchannel device further includes a firstheat transfer manifold having a ring shape that is in fluidcommunication with the plurality of heat transfer microchannels, and asecond reaction manifold having a cylindrical shape that is in fluidcommunication with the plurality of heat transfer microchannels, wherethe plurality of heat transfer microchannels interpose the first heattransfer manifold and the heat transfer reaction manifold. In still afurther detailed embodiment, the plurality of process microchannelscomprises reactant microchannels housing catalyst therein. In a moredetailed embodiment, the plurality of process microchannels comprisesseparation microchannels operative to separate a first component from asecond component.

It is an eighth aspect of the present invention to provide a method ofconducting a reaction comprising passing a composition into an inlet ofa plurality of microchannels that are in parallel to one another, andthrough the plurality of microchannels, and out through an outlet,wherein the plurality of microchannels is defined at least in part by awaveform, where a local contact time is constant along the length of theplurality of microchannels, and where the local contact timeperpendicular to the plurality of microchannels is different.

In a more detailed embodiment of the eighth aspect, a cross-sectionalarea increases across of the plurality of reaction microchannels.

It is a ninth aspect of the present invention to provide a method forchemically reacting a composition in the presence of a catalyst,comprising passing the composition to flow in a direction through aplurality of reaction microchannel containing the catalyst, theplurality of reaction microchannels oriented in parallel to one anotherand at least partially defined by a waveform, where a local contact timeis constant along the length of the plurality of reaction microchannels,and where the local contact time perpendicular to the plurality ofmicrochannels is different.

In a more detailed embodiment of the ninth aspect, the catalyst flowsinto the plurality of reaction microchannels as at least one of aslurry, a liquid, and a dissolved catalyst in a reactant stream. In yetanother more detailed embodiment, the waveform is substantially filledwith a solid, fixed bed catalyst. In a further detailed embodiment, themethod is selected from the group consisting of: acetylation, additionreactions, alkylation, dealkylation, hydrodealkylation, reductivealkylation, amination, aromatization, arylation, autothermal reforming,carbonylation, decarbonylation, reductive carbonylation, carboxylation,reductive carboxylation, reductive coupling, condensation, cracking,hydrocracking, cyclization, cyclooligomerization, dehalogenation,dimerization, epoxidation, esterification, exchange, Fischer-Tropsch,halogenation, hydrohalogenation, homologation, hydration, dehydration,hydrogenation, dehydrogenation, hydrocarboxylation, hydroformylation,hydrogenolysis, hydrometallation, hydrosilation, hydrolysis,hydrotreating (HDS/HDN), isomerization, methylation, demethylation,metathesis, nitration, oxidation, partial oxidation, polymerization,reduction, reformation, reverse water gas shift, sulfonation,telomerization, transesterification, trimerization, and water gas shift.

It is a tenth aspect of the present invention to provide a process unitcomprising a plurality of process microchannels having an inlet and anoutlet, the plurality of process microchannels is defined at least inpart by a waveform, wherein a local contact time is constant along thelength of the plurality of microchannels, and where the local contacttime perpendicular to the plurality of microchannels is different.

In a more detailed embodiment of the tenth aspect, the process unit hasbeen made by laminating sheets. In yet another more detailed embodiment,the plurality of process microchannels comprise a plurality of reactionmicrochannels housing a catalyst therein, and the catalyst comprises aporous material extending between channel walls of the plurality ofreaction microchannels. In a further detailed embodiment, the pluralityof process microchannels comprise a plurality of reaction microchannelshousing a catalyst therein, and the catalyst comprises a porous materialthat touches at least one wall of the plurality of reactionmicrochannels and leaves an open space that extends throughout thelength of at least one of the plurality of reaction microchannels. Instill a further detailed embodiment, the plurality of processmicrochannels comprise a plurality of reaction microchannels housing acatalyst therein, and the plurality of reaction microchannels includemicrochannel walls and the catalyst comprises a catalyst coatingdisposed on the microchannel walls. In a more detailed embodiment, theplurality of process microchannels comprise a plurality of reactionmicrochannels housing a catalyst therein, and at least a portion of theplurality of reaction microchannels is adjacent to a heat exchanger. Ina more detailed embodiment, the plurality of process microchannelscomprise a plurality of reaction microchannels housing a catalysttherein, and at least a portion of the plurality of reactionmicrochannels is adjacent to a plurality of heat exchange microchannels.

It is an eleventh aspect of the present invention to provide a method ofincreasing packing density of particulates loaded into a plurality ofmicrochannels in microchannel apparatus, comprising: (a) providing amicrochannel apparatus comprising a plurality of microchannels havingparticulates contained therein; (b) mounting a portable, compactultrasonic device to a microchannel apparatus, the portable, compactultrasonic device configured to be repositionable between a firstposition where the portable, compact ultrasonic device is in acousticcommunication with the plurality of microchannels and a second positionwhere the portable, compact ultrasonic device is not in acousticcommunication with the plurality of microchannels; and, (c) applyingultrasonic sound to the plurality of microchannels from the portable,compact ultrasonic device to densify the particulates to form a packedbed of particulates within the plurality of microchannels.

In a more detailed embodiment of the eleventh aspect, a sonicallyconductive material is disposed between the portable, compact ultrasonicdevice and the plurality of microchannels. In yet another more detailedembodiment, the ultrasonic sound has a frequency of 20 kilohertz to 40kilohertz. In a further detailed embodiment, at least a portion of theportable, compact ultrasonic device is pressed against the microchannelapparatus with a contact pressure of 200 kilopascals to 280 kilopascals.In still a further detailed embodiment, the ultrasonic sound is appliedin bursts of 30 seconds or less. In a more detailed embodiment, theultrasonic sound is applied in bursts of 10 seconds or less. In a moredetailed embodiment, the ultrasonic sound is applied in bursts of 3seconds or less. In another more detailed embodiment, each microchannelin the plurality of microchannels has a length of at least 10 cm and atleast one dimension of 2 mm or less. In yet another more detailedembodiment, the microchannel apparatus comprises at least 1000microchannels and wherein the portable, compact ultrasonic deviceextends over no more than 500 of the at least 1000 microchannels. Instill another more detailed embodiment, the microchannel apparatuscomprises an insert that extends down the length of at least one of theplurality of microchannels, and the insert transmits sound down thelength of the at least one of the plurality of microchannels.

In yet another more detailed embodiment of the eleventh aspect, themicrochannel apparatus comprises channels at least partly defined bywalls of a wave-shaped insert. In still another more detailedembodiment, the microchannel apparatus comprises a plurality of insertsthat extends down the plurality of microchannels, and the plurality ofinserts transmit sound down the length of plurality of microchannels. Ina further detailed embodiment, the step of applying ultrasonic energy isconducted while the plurality of microchannels are dry. In still afurther detailed embodiment, the plurality of microchannels comprise aplurality of reactant microchannels and the particulates comprisecatalyst contained with the plurality of reactant microchannels. In amore detailed embodiment, the plurality of reactant microchannelscomprise at least 100 microchannels. In a more detailed embodiment, themethod further includes adding particulates into the plurality ofreactant microchannels, and passing a gas through the channels tofluidize the particulate and allowing the particulate to fill themicrochannels. In another more detailed embodiment, the packed bedincludes a void fraction of 0.50 or less. In yet another more detailedembodiment, a pack density of any subset of the plurality ofmicrochannels varies by less than 10 percent.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a process sequence illustration showing various steps offabricating a microchannel module.

FIG. 2 is an elevated perspective view of an exemplary shim part of anexemplary microchannel coolant subassembly for incorporation into themicrochannel module of FIG. 1.

FIG. 3 is an elevated perspective view of an exemplary top plate of anexemplary microchannel coolant subassembly for incorporation into themicrochannel module of FIG. 1.

FIG. 4 is an exploded view of an exemplary microchannel coolantsubassembly showing the orientation of the top plate of FIG. 3 withrespect to the shim of FIG. 2.

FIG. 5 is an elevated perspective view of an exemplary microchannelcoolant subassembly showing the orientation of the top plate of FIG. 3with respect to the shim of FIG. 2 prior to trimming of the shim.

FIG. 6 is a photograph of the structure of FIG. 5 with a portion of thetop plate removed to show how the coolant channels are formed by linearwelds.

FIG. 7 is a magnified end view of a portion of the structure of FIG. 5to show the profile of the coolant channels and how the channels aresealed after the top plate is mounted to the shim.

FIG. 8 is an elevated perspective view of an exemplary coolant panelincorporating four microchannel coolant subassemblies.

FIG. 9 is an exploded view showing the layering of a portion of themicrochannel module of FIG. 1.

FIG. 10 comprises a series of elevated perspective views of someexemplary components comprising a microchannel reactant subassembly.

FIG. 11 is an isolated profile view of an exemplary microchannelreactant subassembly sandwiched between adjacent microchannel coolantsubassemblies.

FIG. 12 is a partially exploded view of a microchannel module of FIG. 1.

FIG. 13 is an elevated perspective view of a microchannel moduleundergoing compression prior to welding the components.

FIG. 14 is an exploded view of the microchannel module of FIG. 1 inaddition to plates to be mounted to the module.

FIG. 15 is an exploded view showing supports that are mounted to theassembly of FIG. 14.

FIG. 16 is an exploded view showing end walls that are mounted to theassembly of FIG. 15.

FIG. 17 is an exploded view showing arcuate walls that are mounted tothe assembly of FIG. 16.

FIG. 18 is an exploded view showing pipes that are mounted to theassembly of FIG. 17.

FIG. 19 is an elevated perspective view of the assembly of FIG. 18.

FIG. 20 is an exploded view showing two arcuate walls that are mountedto the assembly of FIG. 19.

FIG. 21 is an elevated perspective view of the assembly of FIG. 20.

FIG. 22 is an exploded view showing end caps that are mounted to theassembly of FIG. 21.

FIG. 23 is an elevated perspective view of the assembly of FIG. 22.

FIG. 24 is an elevated perspective view of the assembly of FIG. 23 withwelded lids and associated piping.

FIG. 25 is an elevated perspective view of the assembly of FIG. 23 withbolted flanged lids and associated piping.

FIG. 26 is an elevated perspective view of an exemplary microchannelunit operation bank.

FIG. 27 is an elevated perspective view of the assembly of FIG. 24 witha pressure diversion system to maintain external pressure to themicrochannel module.

FIG. 28 is an elevated perspective view of a series of completedmicrochannel modules.

FIG. 29 is an elevated perspective view of a pair of microchannel modulebanks.

FIG. 30 is a partially exploded view of a partially completed exemplarymicrochannel unit operation shown with common inlet and outlet conduitsfor the microchannel module banks.

FIG. 31 is an elevated perspective view from the front of the partiallycompleted exemplary microchannel unit operation shown in FIG. 30.

FIG. 32 is an elevated perspective view of the completed exemplarymicrochannel unit operation of FIG. 31.

FIG. 33 is an elevated perspective view of a partially completed,further exemplary microchannel unit operation.

FIG. 34 is an elevated perspective view of an exemplary reactionsubassembly from the partially completed microchannel unit operation ofFIG. 33.

FIG. 35 is an elevated perspective view of a partially completedmicrochannel unit operation showing vertical placement of one of thecoolant subassemblies therein.

FIG. 36 is an end view of an exemplary coolant subassembly.

FIG. 37 is an elevated perspective view of the completed microchannelunit operation of FIG. 33.

FIG. 38 is an elevated perspective, cross-sectional view of an evenfurther exemplary microchannel unit operation incorporating a bank ofmicrochannel modules.

FIG. 39 is a partially exploded view of the microchannel unit operationof FIG. 38.

FIG. 40 is an elevated perspective view of the microchannel modules andretention rings incorporated into the microchannel unit operation ofFIG. 38.

FIG. 41 is an exploded view of the microchannel modules and retentionrings of FIG. 40.

FIG. 42 is an overhead view of the microchannel modules and retentionrings of FIG. 40.

FIG. 43 is an exemplary tower incorporating a plurality of exemplarymicrochannel unit operations shown in FIG. 38.

FIG. 44 is an exemplary layout schematic showing how the exemplaryembodiments may be integrated with commercially available components.

FIG. 45 is an exploded view of a sub-stack

FIG. 46 is an elevated perspective view of the sub-stack of FIG. 45.

FIG. 47 is a magnified view of a corner of the sub-stack of FIG. 45.

FIG. 48 is an elevated perspective view of an exemplary core.

FIG. 49 is an exploded view of the exemplary core of FIG. 48 withboundary supports.

FIG. 50 is an elevated perspective view of the assembled core andboundary supports.

FIG. 51 is a magnified, elevated perspective view of a joint where areactant boundary support is mounted to a bottom plate.

FIG. 52 is an illustration of a profile view showing how the screen iswrapped around a tube a secured within the peripheral notch using afriction fit.

FIG. 53 is an elevated perspective view of an exemplary microchannelreactor.

FIG. 54 is a partial exploded view of the exemplary microchannel reactorof FIG. 53.

FIG. 55 is a partial exploded view of the exemplary microchannel reactorduring a sequence in the build phase.

FIG. 56 is a partial exploded view of the exemplary microchannel reactorduring a later sequence in the build phase.

FIG. 57 is an elevated perspective view of a series of jointmicrochannel reactors just prior to joining of the second circular endplate.

FIG. 58 is an elevated perspective view of the structure of FIG. 57,shown with a shell.

FIG. 59 is an elevated perspective view of the structure of FIG. 57,shown with a pair of side plates in an exploded fashion.

FIG. 60 is an elevated perspective view of the structure of FIG. 59,shown with the other pair of side plates in an exploded fashion.

FIG. 61 is an elevated perspective view of the structure of either FIG.60 or FIG. 58, shown with half of the manways installed and half of themanways in an exploded fashion.

FIG. 62 is an elevated perspective view of the structure of FIG. 61,shown with the stiffening braces in an exploded fashion.

FIG. 63 is an elevated perspective view of an assembled microchannelunit.

FIG. 64 is an elevated perspective, cut-away view of an exemplarymicrochannel unit showing the mounting location of an exemplary catalystdensification unit.

FIG. 65 is an elevated perspective view, from the front, of theexemplary densification unit of FIG. 66.

FIG. 66 is a rear view of the exemplary densification unit of FIG. 66.

FIG. 67 is an elevated perspective view, from the rear, of the exemplarydensification unit of FIG. 66, shown without part of one rail.

FIG. 68 is a bottom view of an exemplary carriage assembly.

DETAILED DESCRIPTION

It should be understood that the following detailed description ofembodiments of the present invention are exemplary in nature and are notintended to constitute limitations upon the present invention. It isalso to be understood that variations of the exemplary embodimentscontemplated by one of ordinary skill in the art shall concurrently fallwithin the scope and spirit of the invention.

The catalysts described in the following examples may have the advantageof particle sphericity, that is estimated to range from 0.7 to 1 asdefined by Unit Operations of Chemical Engineering, 4^(th) Edition,McCabe, Smith & Harriot, McGraw-Hill Publishing Company, ©1985, pg 137.

As used herein, a “gap” is the smallest dimension of a microchannel.Typically, in a laminated device, the gap is in the stacking direction(i.e., the height). Where the term “gap” is used, preferred embodimentscan be described instead as the height of a microchannel.

Further, as used herein, “portable” refers to anything that is capableof being carried by a human being or is comprised of a relatively fewnumber of components that are themselves able to be carried andassembled by a human being.

As used herein, “compact” refers to anything that is small in size butdoes not sacrifice function for decreased size.

As used herein, “sonic contact” means that the ultrasonic horn is indirect contact with an apparatus through a solid medium (preferablyhaving a thickness of 0.5 cm or less, more preferably 2 mm or less) thattransmits sound.

Also, as used herein, a “microchannel” is a channel having at least oneinternal dimension (wall-to-wall, not counting catalyst) of 10 mm orless, preferably 5 mm or less, and greater than 1 μm (preferably greaterthan 10 μm), and in some embodiments 50 to 2000 μm, with 500 to 1500microns especially preferred when used with a particulate form ofcatalyst; preferably a microchannel remains within these dimensions fora length of at least 1 cm, preferably at least 20 cm. In someembodiments, in the range of 5 to 100 cm in length, and in someembodiments in the range of 10 to 60 cm. Microchannels are also definedby the presence of at least one inlet that is distinct from at least oneoutlet. Microchannels are not merely channels through zeolites ormesoporous materials. The length of a microchannel corresponds to thedirection of flow through the microchannel. Microchannel height andwidth are substantially perpendicular to the direction of flow ofthrough the channel. In the case of a laminated device where amicrochannel has two major surfaces (for example, surfaces formed bystacked and joined sheets), the height is the distance from majorsurface to major surface and width is perpendicular to height. Inpreferred embodiments of this invention, microchannels are straight orsubstantially straight—meaning that a straight unobstructed line can bedrawn through the microchannel (“unobstructed” means prior toparticulate loading). Typically, devices comprise multiple microchannelsthat share a common header and a common footer. Although some deviceshave a single header and single footer, a microchannel device can havemultiple headers and multiple footers. Likewise, a microchannel maycomprise a simple, straight channel or have more complex geometries.

In some apparatus, process channels contain catalyst, sorbents, or heattransfer materials. In exemplary form, the catalyst, sorbents, or heattransfer materials may be in particular form and have a maximum averageparticle size of 5 mm or less, in some other exemplary embodiments evensmaller maximum particle size on the order of 2 mm or less. Somepreferred embodiments include solid materials in a particulate formwhich have an average particle size 0.1 to 10% of the smallest dimensionof the microchannel; some catalysts may have an average particle size of50 micrometers to 1,000 micrometers, or more preferably 100 micrometersto 500 micrometers. The particles may be spherical or have an irregularshape. Catalysts, sorbents, or heat transfer materials may also becoated on microchannel walls or coated on supports, which may beinserted into the microchannel before, during, or after forming thelaminated device.

Heat exchange fluids may flow through heat transfer channels (such as,without limitation, microchannels) adjacent to process channels (suchas, without limitation, reaction micro channels), and may be gases orliquids and may include steam, liquid metals, or any other heat exchangefluids. It is also within the scope of this disclosure to optimize thesystem to include a phase change of the heat exchange fluid. In somefurther exemplary embodiments, multiple heat exchange layers areinterleaved, with multiple reaction microchannels. For example, ten ormore heat exchange layers may be interleaved with ten or more reactionlayers. More specifically, ten or more heat exchange microchannels maybe interleaved with ten or more microchannel reaction layers. By way ofexample, and not limitation, there may be “n” heat exchange layersinterleaved with “m” reaction layers, where “n” and “m” are variableintegers. One or more of these “n” heat exchange layers may include aheat transfer microchannel layer or section of heat transfermicrochannels, while one or more of the “m” reaction layers may includea reaction microchannel layer or section of reaction microchannels.

As used herein, “weld” or “welding” refers to a process of a joiningtogether two or more metal pieces, whether or not one uses a fusiblemetal material that is liquefied proximate a joint of two or more metalpieces and thereafter solidified to unite the two or more metal pieces.An example of welding that does not use a fusible material is laserwelding, where the laser liquefies one or more of the metal piecesthemselves to form a single fused joint.

As used herein, “bonding” refers to a heating process used for joiningpieces in which there is diffusion of elements from one piece to anotherresulting in a joined article with diffused elements near the interface(or near what used to be the interface before bonding). In contrast,“brazing” refers to a process where an interlayer material is sandwichedbetween two or more pieces and melted to contact all exposed surfacesbetween the two or more pieces to join the pieces at each area incontact with the molten interlayer material.

For purposes of this disclosure, “joining” includes welding, bonding,adhesives, brazing and any other process that unites two or more pieces.

As used herein, “unit operation” refers to any chemical reaction,vaporization, compression, chemical separation, distillation,condensation, mixing, heating, or cooling process. A “unit operation”does not encompass, by itself, fluid transport or mixing. But a “unitoperation” may make use of fluid transport and/or mixing.

For purposes of this disclosure, a “microchannel reactor” refers to any“microchannel” having occurring therein at least one chemical reaction.The boundary of a microchannel reactor may be comprised of, withoutlimitation, stainless steel, a Ni-, Co- or Fe-based superalloy such asFeCrAlY, Inconel®, copper, aluminum, glass, ceramics, or plastics. Theprocess layers of the microchannel reactor may be made of a dissimilarmaterial from the heat exchange channels, and in one preferredembodiment the process layers are made from copper, aluminum or othermaterial with a thermal conductivity greater than 30 W/m-K. The choiceof material for the boundary of the microchannel reactor may depend onthe reaction for which the reactor is intended.

Referencing FIG. 1, an exemplary microchannel module device 10 includesa plurality of microchannel coolant and reaction subassemblies 12, 14comprising a stack of layers having a plurality of fluid passageways. Inexemplary form, more than two layers are joined to create an array offluid passageways for the same fluid or a plurality of fluid passagewaysfor two or more fluids.

Heat exchange fluids may flow through microchannels of the coolantsubassemblies 12 adjacent to process channels (such as reactionmicrochannels), and can be gases or liquids and may include steam,liquid metals, or any other known heat exchange fluids. It should alsobe noted that the heat exchange fluid may make use of a phase change tofurther increase the heat capacity of the heat exchange system. As willbe discussed in more detailed hereafter, multiple coolant subassemblies12 are interleaved with multiple reaction subassemblies 14. For example,ten or more coolant subassemblies 12 may be interleaved with ten or morereaction subassemblies 14. Each of these subassemblies 12,14 may containsimple, straight channels or channels with more complex geometries.

Referencing FIGS. 1-7, an exemplary coolant subassembly 12 comprises ashim or laminae 20 containing preformed channels 22 (the channels may beformed by etching) that is joined with a top plate 24. In exemplaryform, the coolant shim 20 comprises a rectangular piece havingdimensions of a width of 7.0 inches, a length of 25.5 inches, and athickness of 0.040 inches. This shim 20 includes a plurality of straightline channels having a depth of 0.020 inches and a width of 0.1 inchesthat are spaced apart with an intervening rib with a width of 0.035 to0.045 inches. Further, the substantially straight channels also containa wavy short section at the front of the channels as shown in U.S.Published Patent Application No. 2007/0246106, Ser. No. 11/738,456,Priority Date Apr. 25, 2006, which is incorporated by reference herein.This lateral spacing between the channels 22 is operative to form a rib26 between adjacent channels that extends the length of the adjacentchannels. In exemplary form, the top plate 24 is also a rectangularpiece, but includes dimensions different than that of the coolant shimand is also substantially planar. By way of example, the top plate 24includes dimension of a width of 6.38 inches, a length of 24.93 inches,and a width of 0.020 inches. After the cooling shim 20 and top plate 24have been formed, assembly of the coolant subassembly 12 occurs.

Assembly of the coolant subassembly 12 includes fixing the position ofthe coolant shim 20 within a holding apparatus (not shown) so thechannels 22 of the coolant shim face upward and do not change inorientation during the assembly process. Thereafter, the top plate 24 islowered over the coolant shim 20 so that the exposed uppermost surfacesof the coolant shim are adjacent the lower surface of the top plate. Asshown in FIG. 5, the top plate 24 is aligned with the coolant shim sothat each edge of the top plate is inset with respect to an edge of thecoolant shim 20. In exemplary form, the medial and lateral sides of thetop plate 24 are each inset 0.310 inches from the nearest edge of thecoolant shim 20, thereby centering the top plate in themedial-to-lateral direction with respect to the coolant shim. Similarly,the proximal and distal sides of the top plate 24 are each inset 0.285inches from the nearest edge of the coolant shim 20, thereby centeringthe top plate in the proximal-to-distal direction with respect to thecoolant shim. After alignment, downward pressure is applied to the topplate 24 and a laser welding process is carried out to join the shim 20and top plate.

Welding of the coolant subassembly requires at least two layers, butcould include three, or more layers comprising a series of top plates 24and shims 20. In exemplary form, a process for fabricating a coolantsubassembly 12 with two layers will be described. As described herein,methods for welding a coolant subassembly 12 include, withoutlimitation, laser welding, resistance welding, friction stir welding,ultrasonic welding, and the like. In particular, the utilization oflaser welding includes fiber lasers such as Yb fiber lasers. Forpurposes of explanation only, laser welding will be utilized.

The laser welding process includes forming a lengthwise weld between thetop plate 24 and each rib 26 of the coolant shim 20 that extends theentire length of the rib. This welding process operates to createseparate coolant channels that extend generally parallel to one another.

The welding process also includes a pair of end laser welds that areformed adjacent the proximal and distal ends of the top plate in orderto seal off the respective coolant channels. The edges of thesubassembly 12 are substantially hermetically sealed to prevent a fluidfrom leaking out the sides and maintaining the continuity of flowpassage so that somewhere between 95-100% of fluid that enters from aninlet leaves the subassembly from the outlet, rather than leaking outthrough the sides or other pathways where flow is not intended. Inalternate embodiments, there may be more than one inlet and/or outletthat is defined by the laminate geometry. As will be discussed brieflyhereafter, these proximal and distal end welds are utilized to fluidtest the effectiveness of the laser welds between the top plate 24 andribs 26. Moreover, as will be discussed in more detail hereafter, theseproximal and distal welds are not incorporated into final microchannelmodule device 10.

In addition to the foregoing welds, the lateral and medial sides eachinclude a pair of laser welds created adjacent the medial and lateraledges of the top plate 24. The welding occurs in regions where, whenstacked in a subassembly, metal is in contact between the layers. It isunderstood that regions comprising a flow channel or a void for fluidsto traverse after the device is manufactured may not necessarily beclosed. It should be noted that the lateral and medial side welds willbe incorporated as part of the final microchannel device. At the end ofthe welding process, a coolant subassembly 12 has been created, butshould be tested and needs to be further processed to create afunctional coolant subassembly.

After the welding process is carried out, the welded top plate 24 andcoolant shim 20 are subjected to pressure testing to verify theintegrity of the welds. Subsequent to validation of the welds, the topplate 24 and coolant shim 20 are processed to arrive at the finalcoolant subassembly 12. This processing includes trimming the edges ofthe rough coolant subassembly to arrive at the final coolant subassemblydimension of 6.0 inches wide and 24.0 inches long.

Referring to FIG. 8, a plurality of final coolant subassemblies 12 areplaced side by side (lateral side of one subassembly contacting thelateral side of another subassembly), flat, and vertically aligned to beflush at the proximal and distal ends. In exemplary form, four coolantsubassemblies 12 are oriented in this fashion and welded along the seamsbetween adjacent coolant subassemblies in order to join thesubassemblies together. The seam weld may be effectuated using variouswelding techniques including, without limitation, laser welding(including fiber laser welding and pulsed laser welding) and tungsteninert gas (TIG) welding. As will be discussed in more detail below, itis not imperative that the entire seam between adjoining coolantsubassemblies 12 be filled. The resulting structure is a square coolantpanel 30 having 24.0 inch sides that is ready to be incorporated in amicrochannel module device 10.

Referring back to FIG. 1, an exemplary microchannel module device 10includes a plurality of coolant subassemblies 12 interposing a pluralityof microchannel reactor subassemblies 14. In exemplary form, the coolantsubassemblies 12 (as part of the coolant panel 30) alternate with layersof microchannel reactor subassemblies 14 to create the fluid passagewaysinside the microchannel module device 10. An exemplary process andstructures used to fabricate the exemplary microchannel module device 10will now be discussed.

Fabricating the microchannel module device 10 includes utilizing a firstendplate 36 as a base upon which to layer successive layers. Inexemplary form, the first end plate 36 has final dimensions of 24.0inches in width, 24.0 inches in length, and 0.25 inches in thickness.Initially, this end plate may have slightly larger dimensions and istrimmed to the final size and includes a series of through orificesextending upon the medial and lateral sides. Upon this end plate 36 ispositioned a first coolant panel 30 so the edges of the coolant panelare centered between the edges of the end plate. Upon the first coolantpanel 30, on the opposite side of the first end plate, is created one ormore microchannel reactor modules 14.

Referencing FIGS. 9-11, in exemplary form, a microchannel reactor module14 includes at least one microchannel reactor within which a chemicalreaction occurs. This reaction may occur within the presence of acatalyst, and the catalyst may be layered upon all or a portion of theboundary of the microchannel reactor and/or be in particulate form to becontained within the boundaries of the microchannel reactor. Pursuant tothis exemplary embodiment, the microchannel reactor module includesdimensions of 24.0 inches in length and 24.0 inches in width.

For purposes of exemplary explanation only, an exemplary reactor module14 comprises at least two support strips 40 extending lengthwise alongthe length of the microchannel reactor. The support strips 40, 42operate to carry the load of adjoining layers without compromising theshape of the reactor microchannel themselves. By way of example, and notlimitation, the reactor module 14 includes an outermost medial andlateral support strips 40 and a pair of interior support strips 42spaced apart and inset with respect to the outermost support strips. Inparticular, the outermost support strips 40 have exemplary dimensions of24.0 inches in length, 0.5 to 3 inches in width (or a narrower range of1 to 2 inches), and 0.125 to 1 inches in thickness (or a narrower rangeof 0.25 to 0.5 inches). Similarly, the interior support strips 42 haveexemplary dimensions of 24.0 inches in length, 0.25 to 1 inches in width(or even a narrower range of 0.25 to 0.5 inches), and 0.125 to 1 inchesin thickness (or even a narrower range of 0.25 to 0.5 inches). Thesesupport strips 40, 42 may be formed of any material that provides therequisite structural support for the microchannel apparatus.

Interposing the support strips 40, 42 are one or more waveforms or finstructures 44 partially defining a boundary of the microchannel. By wayof example, this exemplary embodiment includes three waveforms 44 perreactor subassembly 14, but it should be noted that one, two, or morethan three waveforms may be utilized depending upon the number ofsupport strips utilized. In exemplary form, the reactor subassembly 14includes, from medial to lateral, a medial support strip 40, a firstwaveform 44, a first interior support strip 42, a second waveform 44, asecond interior support strip 42, a third waveform 44, and a lateralsupport strip 40. The waveform or fin structure 44 creates channels orchambers that have an aspect ratio (height to width) greater than one,where the height is the distance between two adjacent coolingsubassemblies 14 and width is the distance between repeating fins oradjacent legs (wave surfaces) of the waveform. By way of example, andnot limitation, the waveform is created from planar foils 46 to have ablock U-shaped repeating pattern operative to cooperate with an adjacentcooling subassembly 14 to define the cross-section of the microchannelreactor. Exemplary dimensions for the waveform 44, include withoutlimitation, a length of 24 inches, a width of 3 to 40 inches (or even anarrower range of 6 to 12 inches), and a height of 0.25 to 1 inches (oreven a narrower range of 0.25 to 0.5 inches). In this exemplaryembodiment, the waveform 44 is fabricated from copper, however anyconductive material may be utilized to partially define the microchannelreactor boundaries.

As discussed above, the microchannel reactor may include catalyst 50.The catalyst may be layered upon all or a portion of the boundary of themicrochannel reactor and/or be in particulate form to be containedwithin the boundaries of the microchannel reactor. In this exemplaryembodiment, the catalyst is in particulate form and packed within thewaveform. Various catalysts may be utilized depending upon theparticular reaction(s) desired within the microchannel. For purposes ofexplanation only, an exemplary Fischer-Tropsch reaction will bediscussed as the reaction to be carried out within the microchannelreactors of the microchannel reactor subassembly. To carry out thisreaction, the catalyst is formulated with Cobalt and promoters, whichmay comprise Platinum, and/or Ruthenium and/or Rhenium to drive theFisher-Tropsch reaction. Those skilled in the art will understand thatvarious catalysts have been developed and are commercially available todrive the Fischer-Tropsch reaction that may be used with the embodimentsof the instant disclosure. Following loading of catalyst 50 into thereactor channels of the waveform 44, the catalyst is activated byexposure to hydrogen at an elevated temperature, for example between 300to 400 C.

Fabrication of the first microchannel reactor module 14 includespositioning the medial and lateral support strips 40 to be substantiallyflush to a corresponding medial/lateral side of the first coolant panel30. Thereafter, the support strips 40 are welded in position to thefirst coolant panel so that the support strips extend parallel to oneanother and flush along corresponding medial and lateral edges of thecoolant panel 30. Likewise, a pair of interior support strips 42 ispositioned on top of the first cooling panel 30 to extend in parallelto, but inset with respect to, the medial and lateral support strips 40and spaced apart from one another and the medial and lateral supportstrips to define three substantially identical and parallel U-shapedcavities. The interior support strips are thereafter welded to the firstcoolant panel. It should be noted that the coolant panel 30 waspositioned so that the microchannel pathways extended along themedial-to-lateral direction. But the support strips 40, 42 are orientedto extend along the proximal-to-distal direction so that the U-shapedcavities extend perpendicular to the microchannel fluid conduits of thefirst coolant panel 30. A waveform 44 is positioned within each U-shapedcavity between the supports 40, 42 so that the proximal and distal endsof the waveform are substantially flush with the proximal and distalends of the first coolant panel 30. At the same time, the waveform hasalready been created so that is fits in a friction fit arrangementbetween corresponding supports 40, 42. But is should also be noted thatthe waveform 44 effectively floats on top of the coolant panel 30because the waveform is neither welded to the supports 40, 42, nor tothe underlying first coolant panel. This waveform insertion finishesfabrication of the components comprising the first reactor subassembly14.

After the first reactor subassembly has been fabricated, approximatelyhalf of the microchannel reactors have completely bounded conduits alongtheir longitudinal length (extending in the proximal-to-distaldirection). More specifically, these microchannel reactors have parallelside walls and a top wall formed by the waveform 44, while the bottomwall is formed by the exposed surface of the coolant panel 30. But tofinish the remainder of the microchannel reactors (because some of thereactors are missing a top wall), a second coolant panel 30′ ispositioned over the first reactor subassembly 14. This second coolantpanel 30′ is fabricated just as the first coolant panel was fabricated.The second coolant panel 30′ is laid over the first reactor subassembly14 so that the microchannels extend perpendicular to the reactormicrochannels of the first reactor subassembly. The second coolant panel30′ is aligned so that its medial and lateral edges are substantiallyflush with the medial and lateral edges of the supports 40, while theproximal and distal edges of the coolant panel are substantially flushwith the proximal and distal edges of the supports 40, 42. Thereafter,the process for forming a reactor subassembly 14 is replicated on top ofthe second coolant panel 30′. This process of placing cooling panels 30on top of a first reactor subassembly 14 and thereafter constructing asecond reactor subassembly on top of the cooling panel is repeated untilthe microchannel module is completed and the uppermost cooling paneldoes not have a reaction subassembly fabricated on its uppermostsurface. Instead, this uppermost cooling panel is topped with a secondendplate 36 to finish the module stacking sequence.

Referring to FIGS. 12 and 13, the stack 10 is placed between two clampplates 37 which include a series of through orifices extending upon themedial and lateral sides to receive fasteners 54. These fasteners 54, inexemplary form, comprise bolts and nuts operative to be tightened tocompress the clamp plates 37 toward one another, likewise compressingthe cooling plates 30 and reaction subassemblies 14 therebetween. Afterthe appropriate compression is achieved, the proximal and distal ends ofthe cooling plates 30, reaction subassemblies 14, and endplates 36 arewelded together. The fasteners 54 and clamp plates 37 may then beremoved to weld the medial and lateral ends of the cooling plates 30,reaction subassemblies 14, and endplates 36 together. The welding mayuse different types of welding methods including, without limitation,TIG, MIG, laser welding, and electron beam welding. As will be discussedbelow, this microchannel module 10 and others similarly fabricated maybe utilized to create various microchannel unit operations.

Referring to FIGS. 14-24, a first exemplary microchannel unit operation100 makes use of at least one microchannel module 10 mounted to anexoskeleton operative to direct inputs to the microchannel module andoutputs from the microchannel module, as well as provide compressionagainst sealed portions of the microchannel module. For purposes ofexplanation only, it will be presumed that the microchannel module 10has been fabricated for use with a Fischer-Tropsch process, although theinventive reactor could be used with other high pressure reactions.Accordingly, the fabrication and discussion of the component parts ofthe first exemplary microchannel unit operation 100 will be described interms of a Fischer-Tropsch microchannel unit operation. But thoseskilled in the art will understand that the following fabrication andintegration of a microchannel module 10 may be readily adapted tonumerous other processes without significant alteration.

Referencing FIG. 14, an exemplary microchannel module 10 is utilized asthe core of the Fischer-Tropsch microchannel unit operation 100. Thisincludes fabricating the microchannel unit operation to include at leastone microchannel reactor adapted to carry out a Fischer-Tropschreaction. Consistent with this approach, the top and bottom of themicrochannel module 10 include solid endplates 36 to which are mountedrespective rectangular plates 104 having generally the same width as themicrochannel module, but having a length greater than the microchannelmodule to overhang the open sides of the microchannel module comprisingthe microchannel reactors. In other words, the microchannel module 10includes a plurality of reactor microchannels that are open on opposingsides of the module. It is these open, opposed sides that the plates 104overhang, as opposed to the open sides of the module 10 that are part ofthe coolant panels 30. In exemplary form, the plates 104 may befabricated from stainless steel or other metal and include exemplarydimensions of 33.1 inches in length, 24.6 inches in width, and 0.75inches in thickness. In this exemplary embodiment, the plates 104 arewelded to the endplates 36 of the microchannel module 10 at the outerseams where the plates and endplates come together. Exemplary welds thatmay be used to secure the plates 104 to the endplates 36 include,without limitation, fillet welds created using any standard weldingprocess (TIG, MIG, laser, etc).

Referring to FIG. 15, after the plates 104 have been mounted to themicrochannel module 10, four rectangular supports 108 are mounted to themicrochannel module 10 and to the plates. Each of the supports 108 maybe fabricated from stainless steel or other metal and include exemplarydimensions of 24 inches in length, 4.5 inches in width, and 0.75 inchesin thickness. The supports 108, when coupled to the plates 104 andmodule 10, provide a series of perpendicular supports extending from themodule 10 and the plates. More specifically, each support 108 is mountedto a respective corner of the module 10 and a peripheral side of arespective plate 104 to create an enclosed, rectangular periphery ateach side of the module providing a single rectangular opening on eachside for egress to and from the microchannel reactors. In this exemplaryembodiment, the supports 108 are welded to the plates 104 and corners ofthe microchannel module 10 at the outer seams where the plates, corners,and supports come together. Exemplary welds that may be used to securethe supports 108 to the plates 104 and corners of the module 10 include,without limitation, full penetration welds created using any standardwelding process (TIG, MIG, laser, etc).

Referring to FIG. 16, after the supports 108 are mounted to the plates104 and corners of the module 10, four end walls 112 are mounted to thesupports. In exemplary from, each of the end walls 112 includes a linearside that is mounted to a respective support 108 to extendperpendicularly away from the support to partially define what will berespective, single openings on opposite sides of the module 10 foregress to and from the microchannels of the coolant panels 30. Thelinear side of each end wall is joined by a uniform arcuate side tocreate a solid wall that resembles a semicircular shape. It should benoted that one may choose to use other shapes for pressure containment,however, a curved shape requires generally less material. In exemplaryform, each end wall 112 may be fabricated from stainless steel or othermetal and include exemplary dimensions of 24 inches in length along thestraight side, 27 inches in length along the arcuate side, and 0.75inches in thickness. More specifically each end wall 112 is insetapproximately 1 inch with respect to a corresponding support 108 andwelded to the support along the linear side. The ends where the linearside and arcuate side merge are also welded to the plates 104. Exemplarywelds that may be used to secure the end walls 112 to the plates 104 andsupports 108 include, without limitation, full penetration welds createdusing any standard welding process (TIG, MIG, laser, etc). Whencompleted, the end walls 112 on the same side of the module 10 comprisebookends that are generally parallel to one another.

Referencing FIGS. 17-19, subsequent to end wall 112 installation, a pairof exemplary arcuate, rectangular walls 116, 118 are mounted to oppositesides of the module 10. More specifically, the first arcuate,rectangular wall 116 includes a through orifice 120 to accommodate aninlet pipe 122 operative to direct coolant into fluid communication withthe microchannels of the coolant panels 30. In exemplary form, the wall116 may be fabricated from stainless steel or other metal and includesexemplary dimensions of 31 inches in length, 35 inches in diameter, and0.75 inches in thickness. Moreover, the inlet pipe 122 may be fabricatedfrom stainless steel or other metal and include exemplary dimensions of12 inches in length, 4 inches in diameter, and 0.5 inches in thickness.

In order to provide this fluid communication, the perimeter of the inletpipe 122 is welded to the perimeter of the wall 116 defining the orifice120 in order to close off the orifice on the side of the inlet pipe.Alternatively, the rectangular wall 116 may include a built-in nozzlewith a flange that is connected to a pipe flange. The wall 116 is alsomounted to the top and bottom plates 104, as well as to the two endwalls 112 that are bookends on the coolant inlet side of the module 10.In this exemplary embodiment, the wall 116 is welded the top and bottomplates 104 along the seam where the plates 104 meet the wall. Inaddition, the wall 116 is also welded to the arcuate sides of the endwalls 112 along the seam where the walls meet. Exemplary welds that maybe used to secure the wall 116 to the end walls 112 and the plates 104include, without limitation, full penetration welds created using anystandard welding process (TIG, MIG, laser, etc). When the welding of thewall 116 is completed, a fluid tight seal is formed so that fluid cominginto the microchannels of the coolant panels 30 can only come throughthe inlet pipe 122. It should be noted that the length of the wall 116is not as great as the aggregate length of the module 10 in combinationwith the supports. Accordingly, the wall 116 is inset 1 inch from theends of the supports 108.

On the opposite side of the module 10, from the inlet wall 116, theoutlet wall 118 includes a pair of orifices 124, 126 to accommodate avapor outlet pipe 128 and a liquid outlet pipe 130 operative to directcoolant liquid and vapor coolant out of the microchannels of the coolantpanels 30. In exemplary form, the wall 118 may be fabricated fromstainless steel or other metal and includes exemplary dimensions of 31inches in length, 35 inches in diameter, and 0.75 inches in thickness.Moreover, the outlet pipes 128, 130 may be fabricated from stainlesssteel or other metal and include exemplary dimensions of 12 inches inlength, 2 inches in diameter, and 0.375 inches in thickness.

In order to provide fluid communication between the pipes 128, 130 andthe outlet of the microchannels of the coolant panels 30, the perimeterof the both pipes 128, 130 is welded to the perimeter of the wall 118defining the respective orifice 124, 126 in order to close off theorifice on the side of the outlet pipe. The wall 118 is also mounted tothe top and bottom plates 104, as well as to the two end walls 112 thatare bookends on the coolant outlet side of the module 10. In thisexemplary embodiment, the wall 118 is welded the top and bottom plates104 along the seam where the plates 104 meet the wall. In addition, thewall 118 is also welded to the arcuate sides of the end walls 112 alongthe seam where the walls meet. Exemplary welds that may be used tosecure the wall 118 to the end walls 112 and the plates 104 include,without limitation, fall penetration welds created using any standardwelding process (TIG, MIG, laser, etc). When the welding of the wall 118is completed, a fluid tight seal is formed so that fluid coming out ofthe microchannels of the coolant panels 30 can only exit through theoutlet pipes 128, 130. As with the other wall 116, this outlet wall 118is inset 1 inch from the supports 108.

Referring to FIGS. 20-23, after the walls 116, 118 and pipes 122,128,130 have been mounted, a pair of covers 134 and end cap 136 are mountedto the assembly. In particular, each cover 134 comprises an arcuaterectangle having a widthwise dimension and a lengthwise dimension thatclosely approximates the widthwise and lengthwise dimensions of theplates 104. But, similar to the walls 116, 118, the covers 134 are inset1 inch from the supports 108. In exemplary form, the covers 134 may befabricated from stainless steel or other material and include exemplarydimensions of 31 inches in length, 35 inches in diameter, and 0.75inches in thickness.

In particular, each cover 134 is oriented so its lengthwise dimensionoverlies the lengthwise portion of a respective plate 104, as well asthe widthwise portion of the cover overlying the widthwise portion ofthe respective plate. The covers 134 are then positioned adjacent to arespective plate 104 and welded at the widthwise seam where the coverand respective endplate meet. After the covers 134 are mounted to theplates 104, the resulting structure creates a cylindrical profile havinga circular cross-section open at the ends of the microchannel module 10in communication with the reaction microchannels, as well as theresulting conduits 140 defined by the interior of the covers and theexteriors of the plates. In order to close the conduits and inhibitfluid communication between the interior of the conduits and thereaction microchannels, respective end caps 136 are mounted to theassembly.

Each end caps 136 may be fabricated from stainless steel or other metaland includes a circular shape having exemplary dimensions of 35 inchesin diameter and 0.75 inches in thickness. Both end caps 136 include arectangular opening having dimensions of 24 inches in length and 24inches in width. In particular, the rectangular opening has generallythe same rectangular dimensions as the perimeter formed cooperatively bythe plates 104 and the supports 108 at the respective ends of theassembly. Each end cap 136 is sized to be match the circumference of thecylindrical shape defined by the covers 134 and the walls 116, 118 inorder to close off the conduits 140 and provide a secondary closure forthe coolant side. Accordingly, one face of each end cap 136 is welded tothe longitudinal ends of the covers 134 and the walls 116, 118 to besubstantially normal to these covers and walls. At the same time, eachend cap 136 is welded to the exposed longitudinal ends of the plates 104and the supports 108. The net result is that a single, fluid tight,rectangular opening exists at the respective longitudinal ends that feedinto and out of the microchannel reactors of the microchannelsubassemblies 14. At the same time, the end caps 136 are operative tocooperatively define a pair of sealed cavities with the plates 104 andthe covers 134. These sealed cavities may be occupied by a pressurizedfluid in order to apply a positive pressure on the exterior of theplates. This exemplary Fischer-Tropsch microchannel unit operation 100is different from conventional approaches, in part, in that the sealedcavities on the outside of the module 10 are in fluid communication witha pressurized fluid. The pressurization fluid (e.g., water, nitrogen,Fisher-Tropsch reactant(s)) may be different between the cavities andmay be supplied to the cavities to ensure that pressurized fluid isalways maintained on the outside of the module 10.

Referring to FIGS. 24 and 25, adapting the Fischer-Tropsch microchannelunit operation 100 to receive inlet streams and distribute outletstreams from the unit operation may be accomplished using varioustechniques and structures. FIG. 24 shows a first exemplary structure 100where the inlet end to the microchannel reactor subassemblies and theoutlet from the microchannel reactor subassemblies is sealed with awelded connection. In particular, a first lid 144 having a having anorifice to receive an inlet pipe 146 is welded to each exposed end ofthe assembly. More specifically, the lid 144 comprises a dome-shapedstructure having a circular opening at one end and the orifice extendingthrough the dome. In exemplary form, the lid 144 may be fabricated fromstainless steel or other metal and includes exemplary dimensions of 35inches in diameter, 6 inches in height, and 0.75 inches in thickness.The circular opening of the lid 144 is welded to the opposing face(opposite the remainder of the assembly) of the end cap 136 to create afluid tight seal therebetween. In order to ensure that only fluid fromthe pipe 146 reaches the interior of the reaction microchannels of thereaction subassemblies 14, the pipe is welded to the lid 144 to create afluid tight seal therebetween. Likewise, the second lid 148, which isvirtually identical to the first lid, includes an outlet orifice towhich an outlet pipe 150 is welded to create a fluid tight seal.Similarly, the second lid 148 is welded to the opposite exposed end ofthe assembly to close off the outlet end of the module, thereby ensuringall fluid flowing through the reaction microchannels of the reactionsubassemblies 14 that exit the module 10 are directed through the outletpipe 150.

FIG. 25 shows a second exemplary structure 100′ that is identical to thefirst exemplary structure 100, with the exception that a pair of flanges160, 162, 164, 166 interpose the end caps 136 and the lids 144, 148. Thecircular opening of the first lid 144 is welded to a ring-shaped flange160 having a series of openings adapted to receive fasteners (notshown), such as nuts and bolts, to removably secure the first lid to theremainder of the assembly. In order to do this, the assembly includesanother ring-shaped flange 162, having corresponding openings adapted toreceive fasteners, that is welded to the end cap 136. The basis for thisremovable structure, in part, stems from the desire to replace orregenerate the catalyst, or to inspect, refurbish, or repair the core,with the reaction subassemblies 14 after a predetermined period. Whilethe first exemplary structure also allows replacement and regenerationof the catalyst, replacement of the catalyst may require cutting the lid144 from the end cap 136. This second exemplary structure obviates anyneed to cut the lid from the end cap 136 by making the end cap removablesimply by removing the fasteners from the flanges 160, 162 and removingthe top flange 160 and end cap. Similar to the inlet side, the outletlid 148 is welded to a ring-shaped flange 168 having a series ofopenings adapted to receive fasteners (not shown), such as nuts andbolts, to removably secure the lid 148 to the remainder of the assemblyvia a connection to a complementary flange 166 welded to thecorresponding end cap 136. As with the top lid, the bottom lid 148 isreadily removable from the remainder of the assembly simply by removingthe fasteners holding the flanges 166, 168 together.

Referring to FIG. 26, the first and second exemplary structures 100,100′ may be fabricated in multiples and oriented in parallel to oneanother to create a bank of microchannel structure 280. For purposes ofexemplary depiction only, the exemplary structure 100′ is shownrepetitively in FIG. 26 to create the bank. This bank 280 is connectedto a common feed conduit 282 operative to distribute raw material toeach inlet pipe 146, thereby delivering raw material to the interior ofthe reaction microchannels of the reaction subassemblies. Each of theoutlet pipes 150 is also connected to a common product conduit 284 inorder to gather product from the reaction microchannels of eachexemplary structure 100, 100′. Similarly, the inlet pipes 122 of theexemplary structures 100, 100′ are in fluid communication with a singlecooling fluid conduit 286 operative to direct coolant into fluidcommunication with the microchannels of the coolant panels. Downstreamfrom the microchannels of the coolant panels are the respective vaporoutlet pipes 128 and liquid outlet pipes 130 to direct coolant liquidand vapor coolant out of the microchannels. In exemplary form, the vaporoutlet pipes 128 are all in fluid communication with a common coolantvapor conduit 288, while all of the liquid outlet pipes 130 are in fluidcommunication with a common coolant liquid conduit 290. In this manner,a single conduit 288 carries the coolant vapor collected from theexemplary structures 100, 100′, while a single conduit 290 carries thecoolant liquid collected from the exemplary structures.

Referring to FIG. 27, in an alternate exemplary embodiment 200, eitherexemplary structure 100, 100′ may include a positive pressure structure202. For purposes of exemplary depiction only, the exemplary structure100 is shown in FIG. 27 with the positive pressure structure. Thispositive pressure structure 202 includes an inlet pipe 204 supplying apressurized fluid to the interior of the cavities by way of a respectiveegress orifice through the covers 134. By way of example, and notlimitation, the pressurized fluid may be in inert fluid such as nitrogenthat is directed into the cavities at a pressure greater than thepressure within the reaction microchannels of the reaction subassemblies14. In this manner, the pressurized fluid provides a positive pressureupon the exterior of the microchannel module 10. But in a circumstancewhere, for whatever reason, the pressure of the pressurized fluid is nolonger at or above the pressure occurring within the reactionmicrochannels of the reaction subassemblies 14, a diverter pipe 206 influid communication with the inlet pipe 146 will direct reactantsflowing through the inlet pipe through the diverter pipe and through acheck valve or pressure regulator 208, the outlet side of which is influid communication with the inlet pipe 204. It should also be notedthat the inlet pipe 204 also includes a check valve 212 upstream fromthe connection to the outlet side of the first check valve 208. WhileFIG. 27 may be alleged to only show the inlet pipe 204 in communicationwith one of the cavities, it should be understood that the inlet pipe204 is in communication with both cavities on opposite sides of themodule 10. In this manner, if any or all cavities exhibit pressure lessthan the pressure within the diverter pipe, the contents of the diverterpipe will flow through the inlet pipe 204 and into the cavity orcavities in question.

In operation, presuming the reactor microchannel are operating at apressure “X” and the pressurized fluid is supplied at a pressure “Y”,which is higher than pressure X, then the first check valve 208 would beclosed to inhibit pressurized fluid from entering the diverter pipe 206and into communication with the reactant inlet pipe 146. But, forwhatever reason, if pressure Y drops below pressure X, the first checkvalve 208 is opened to allow a portion of the reactant stream from thereactant inlet pipe 146 to flow into the diverter pipe 206, through thefirst check valve, and through the inlet pipe 204 to the interior of thecavities so that the pressure within the cavities is at least as greatas the pressure within the reaction microchannels of the reactionsubassemblies 14. But when pressure Y drops below pressure X, the secondcheck valve 212 is closed to ensure that pressure within the cavities ismaintained and the reactants are not able to bleed out upstream from thesecond check valve.

Referring to FIGS. 28-32, a third exemplary embodiment of a microchannelunit operation 300 makes use of a plurality of microchannel modules 10mounted end to end with the inlet sides for the coolant subassemblies 12all face the same direction, as well as the inlet sides of themicrochannel reactor subassemblies 14 all facing the same direction.More specifically, the endplates 36 of each module 10 are adjacent oneanother in a compression fit. In exemplary form, ten microchannelmodules 10 are oriented end to end so that the top endplate 36A of afirst module 10A is adjacent and aligned to completely overlap thebottom endplate 36B of a second module 10B. This pattern is repeated forany number of modules, but in this example, ten modules. After themodules have been oriented end to end, the seams between the endplates36 of adjacent modules are welded to couple the adjacent modulestogether to create a microchannel module bank 302. In particular, eachof the microchannel modules 10 of the first bank 302A have beenfabricated so that in a clockwise direction the module includes an inletside for the coolant subassemblies 12, an outlet side for themicrochannel reactor subassemblies 14, an outlet side for the coolantsubassemblies, and an inlet side for the microchannel reactorsubassemblies 14. Conversely, the microchannel modules 10 of the secondbank 302B have been fabricated so that in a clockwise direction themodule includes an inlet side for the coolant subassemblies 12, an inletside for the microchannel reactor subassemblies 14, an outlet side forthe coolant subassemblies, and an outlet side for the microchannelreactor subassemblies 14.

Referring to FIG. 30, the microchannel module banks 302A, 302B arealigned in parallel to one another and spaced apart from one another sothat the inlet sides of each of the coolant subassemblies 12 face oneanother. This orientation also has means that the outlet sides of eachof the coolant subassemblies 12 face in opposite directions. Moreover,this orientation results in the inlet side for the microchannel reactorsubassemblies 14 both facing in a first direction, and the outlet sidefor the microchannel reactor subassemblies 14 both facing in a seconddirection opposite that of the first direction.

Fabrication of the third exemplary microchannel unit operation 300includes welding a pair of semicircular linear conduits 310, withsemicircular end walls 312, to each of the microchannel module banks302A, 302B adjacent the inlet side of the microchannel reactorsubassemblies 14 (see FIG. 1). In particular, each of the linearconduits 310 has a widthwise dimension that roughly equals the widthwisedimension of the respective microchannel module banks 302A, 302B so thatwelding of the conduits at the seams where the conduits meet the edgesof the module banks creates a fluid tight seal therebetween. At the sametime, the end walls 312 are welded to the longitudinal ends of themodule banks 302A, 302B to ensure that all fluid entering the inlet sideof the microchannel reactor subassemblies 14 has been conveyed via thelinear conduits 310. Each linear conduit 310 also includes an inlet pipe314 welded thereto and operative to supply reactant to the inlet side ofthe microchannel reactor subassemblies 14.

A second pair of semicircular linear conduits 320, with semicircular endwalls 322, is welded to each of the microchannel module banks 302A, 302Badjacent the outlet side of the microchannel reactor subassemblies 14.In particular, each of the linear conduits 320 has a widthwise dimensionthat roughly equals the widthwise dimension of the respectivemicrochannel module banks 302A, 302B so that welding of the conduits atthe seams where the conduits meet the edges of the module banks createsa fluid tight seal therebetween. At the same time, the end walls 322 arewelded to the longitudinal ends of the module banks 302A, 302B to ensurethat all fluid exiting the outlet side of the microchannel reactorsubassemblies 14 has been conveyed via the linear conduits 320. Eachlinear conduit 320 also includes an outlet pipe 324 welded thereto andoperative to carry away product from the outlet side of the microchannelreactor subassemblies 14.

A third pair of semicircular linear conduits 330, with semicircular endwalls 332, are welded to each of the microchannel module banks 302A,302B adjacent the outlet side of the coolant subassemblies 12. Inparticular, each of the linear conduits 330 has a widthwise dimensionthat roughly equals the widthwise dimension of the respectivemicrochannel module banks 302A, 302B so that welding of the conduits atthe seams where the conduits meet the edges of the module banks createsa fluid tight seal therebetween. At the same time, the end walls 332 arewelded to the longitudinal ends of the module banks 302A, 302B to ensurethat all fluid exiting the outlet side of the coolant subassemblies 12has been conveyed via the linear conduits 330. Each linear conduit 330also includes an outlet pipe 334 welded thereto and operative to carryaway coolant from the outlet side of the coolant subassemblies 12.

A pair of longitudinal plates 340 are welded across the tops and bottomsof the remaining, otherwise exposed inlet sides of the coolantsubassemblies 12, to create a fluid tight seal, as are an inlet cap 342and a rear cap (not shown) mounted to the front and rear to close offthe remaining openings and create a fluid tight seal. The plates 340 andcaps 342 cooperate to inhibit fluid from entering the inlet side of thecoolant subassemblies 12 except through a coolant inlet pipe 346 weldedto the inlet cap 342.

Referring to FIGS. 33-37, a further exemplary microchannel unitoperation 400 is cylindrical and provides coaxial coolant delivery andreactant delivery. More specifically, the cylindrical shape is theresult of a series of microchannel coolant and reaction subassemblies402, 404 that alternate in a circular arrangement. In this exemplaryembodiment 400, the microchannel coolant subassemblies 402 each comprisea shim or laminae 408 with preformed channels 410 (the channels may beformed by etching) that is joined with a top plate 412. In exemplaryform, the preformed channels 410 are linear and extend horizontally. Inexemplary form, the coolant shim 408 comprises a rectangular piecehaving constant dimensions of a width of 24 inches, a length of 24inches, and a variable thickness that changes to accommodate for thedifference in circumference on the interior of the unit operation 400and the exterior of the unit operation. Alternatively, the coolant shim408 may comprise a rectangular piece having a constant thickness anddimensions of a width of 24 inches and a length of 24 inches. By way ofexample, and not limitation, the shim 408 may have a frustopyramidalhorizontal cross-section or a rectangular horizontal cross-section.

Referring specifically to FIG. 36, a graphical depiction shows how thecross-section of an exemplary the coolant microchannel 414 may changebetween the interior and the exterior of the coolant subassembly 402. Inexemplary form, the coolant microchannel has a cross-section that isdefined by the bottom, flat surface of the top plate 412 and theinterior, concave surface of the shim 408 that delineates the preformedchannels 410. Between the interior and the exterior of the unitoperation 400, the profile of the coolant channel 414 generally remainsthe same shape, but the cross-section of the coolant channel 414increases proportionally to the increase in thickness of the shim in theradial direction.

Alternatively, the exemplary coolant microchannel may extend radially(as opposed to parallel to the axial center) from the center of the unit400 in parallel with the reaction microchannels 422 discussed below. Insuch a circumstance, the exemplary coolant microchannels may exhibit aconstant radial cross-section (and just have the material defining themicrochannel increase as the radial distance increases) or may have across-section that increase as the radial distance from the centerincreases. The profile of the exemplary coolant microchannels thatextend radially may take on various forms such as, without limitation,rectangular, square, circular, and oblong.

One of the advantages of the approach of FIGS. 33-37 is that themicrochannel unit operation 400 is “self-supporting”. In contrast,current rectangular unit operations counterbalance the pressure in anyprocess layer by the pressure in the layers adjacent to it on eitherside. A potential problem arises at the ends where the outermost processlayer is only counterbalanced on one side, but nothing on the other side(e.g., ambient conditions). To balance this pressure, it is known to useexternal supports to keep the unit operation from deforming. But if youarrange the process layers in a circular fashion, as with the exemplaryunit operation 400, there is no “outlayer” and therefore every processhas adjacent layers on both sides to balance the pressure. This mayresult in the absence of external supports and less material used toconstruct the unit operation, which may result in the unit operationweighing less and increasing its process throughput per unitdisplacement. Moreover, the less material used to construct the unitoperation, less the cost for a comparable unit operation.

Referencing FIGS. 35 and 36, a joining process, preferably a laserwelding process is carried out to attach the top plate 412 to the shim408, thus forming a lengthwise weld between the top plate and a rib 416of the coolant shim 408 that extends the entire length of the rib. Thiswelding process operates to create separate coolant channels 414 thatextend generally parallel to one another in a radial direction from theaxial center of the unit operation 400. Interposing the microchannelcoolant subassemblies 402 are the reaction subassemblies 404.

Referring to FIGS. 33, 34 and 36, the reaction subassemblies make use ofthe top plate 412 from a first adjacent coolant subassembly 402 and theshim 408 from a second adjacent coolant subassembly in order to sandwicha corrugated insert 420 therebetween. In exemplary form, the corrugatedinsert 420 comprises a waveform having a series of repeating unitshaving a block U-shaped profile that extends vertically to definegenerally rectangular cross-sectioned cavities 422, perpendicular to thehorizontal coolant channels 414 of the coolant subassemblies 402. Thisblock U-shaped profile increases as the distance from the axial centerof the unit operation increases. By way of example, the insert 420includes dimensions of a width of 24 inches, a length of 24 inches, anda variable thickness corresponding to the distance from the axialcenter. In this exemplary embodiment, the thickness gradually increasesfrom 0.063 inches at the interior of the unit operation 400 to 0.313inches at the exterior of the unit operation. By way of example, and notlimitation, the insert 420 has outer boundaries that resemble afrustopyramidal horizontal cross-section. Within the cavities 422 of theinsert 420 may be located a catalyst (not shown) such as, withoutlimitation, a FT catalyst. This catalyst may be coated on the walls ofthe insert 420 and/or be located within the cavities 422 in particulateform.

Referring back to FIG. 33, the interior and the exterior of the unitoperation 400 includes corresponding interior and exterior cylindricalbands 430, 432 to facilitate packing of the coolant and reactionsubassemblies 402, 404. The interior coolant band 430 includes aplurality of through openings (not shown) that are aligned with theopenings to the coolant microchannels 414 nearest the radial center inorder to provide fluid communication between the interior of theinterior band and the coolant microchannels. The exterior coolant band432 includes a plurality of through openings (not shown) that arealigned with openings egressing from the coolant microchannels 414,farthest from the radial center, in order to provide fluid communicationbetween the exterior of the exterior band and the coolant microchannels.

Referring to FIG. 37, a single coolant inlet pipe 440 is welded to theinterior cylindrical band 430 in order to supply coolant to the interiorof the cylindrical band and thereafter through the coolant microchannels414. In order to gather coolant exiting the coolant microchannels 414, aring-shaped envelope 444 is welded to the exterior of the cylindricalband 432 in order to provide a sealed cylindrical cavity enveloping thecylindrical band and gathering all of the coolant that exits themicrochannels. In exemplary form, the envelope 444 includes a pair ofpipes 446, 448 that respectively carry the liquid phase and the vaporphase of coolant exiting the coolant channels. Raw materials isdelivered to the reactant subassemblies using a feed pipe 452 welded toa hollow, ring-shaped cap 454, which is itself welded to the top rims ofthe cylindrical bands 430, 432. In this manner, a fluid tight seal iscreated between the interior of the feed pipe 452 and the reactionmicrochannels. At the same time, this fluid tight seal prohibits mixingof the inlet coolant stream with the raw material(s) flowing into thereaction microchannels. Similarly, the outlet side of the reactionmicrochannels includes a hollow, ring-shaped cap 458, which is itselfwelded to the bottom rims of the cylindrical bands 430, 432 to create afluid tight seal and capture all of the materials flowing out of thereaction microchannels. This cap 458 has an orifice partially defined byan outlet pipe 460 welded to the cap to convey the outlet stream fromthe cap.

Referring to FIGS. 38-42, a plurality of microchannel modules 10 areincorporated into an even further exemplary microchannel unit operation500. This exemplary microchannel unit operation 500 incorporates eightmicrochannel modules 10 using a series of retention rings 502 that arevertically spaced apart from one another and welded to the microchannelmodules. As shown in FIGS. 40 and 41, five retention rings 502 areequally spaced apart from one another, where the top of the five ringsis mounted at the perimeter top edge of each of the modules 10 and thebottom of the five rings is mounted at the perimeter bottom edge of eachof the modules. In order to facilitate mounting to the modules 10, eachof the retention rings 502 has the same shape. This shape is circularand includes a diameter of 144 inches and a thickness of 0.75 inches. Anaxially centered circular hole 506 is formed through each retention ring502. Circumferentially interposing the circular hole 506 are eightsquare holes 508 that are sized to match the exterior perimeter of themodules 10. In exemplary form, the square holes have a side length of 24inches. Each of the square holes 508 is equidistantly spaced apart fromthe other holes 508, but the holes are closer to the circular hole 506than to the circumferential perimeter 510 of the rings. As will bediscussed in more detail below, this additional spacing from the holes508 to the circumferential edge provides for additional space in orderto separate the coolant vapor from the coolant liquid exiting themicrochannel coolant subassemblies.

Referencing FIG. 38, in order to ensure fluid communication between aninlet coolant pipe 514 and the interior of the coolant microchannels, aseries of vertical dividers 516 interpose the rings 502 and cooperatewith the rings to define a rectangular opening that is in sealed fluidcommunication with the interior of the inlet coolant pipe 514, but isnot in ready communication with the exterior of the microchannel module.In this exemplary embodiment, the coolant bathes the microchannelmodules 10 and the exterior of the modules is in intimate contact withthe coolant exiting the modules, except for the faces in communicationwith the reactor microchannels. In this exemplary embodiment, the inletcoolant pipe 514 extends through the circular hole 506 of each ring 502and includes a series of circumferential openings adapted to align withthe coolant microchannel subassembly openings of the modules. In thismanner, the inlet pipe 514 supplies the coolant to all of the modules 10at the same time.

In order to capture the coolant exiting the modules 10, the rings 502are circumferentially bounded by a circular band 518. The top ring 502also includes a perimeter opening (not shown) that is circumscribed by acoolant vapor outlet pipe 520 in order to collect and draw off coolantvapor exiting the modules 10. Likewise, the bottom ring 502 includes aperimeter opening (not shown) that is circumscribed by a coolant liquidoutlet pipe 524 in order to collect and draw off coolant liquid exitingthe modules 10.

Referring to FIGS. 38 and 39, interposing the inlet coolant pipe 514 andthe outlet coolant pipes 520, 524 are a pair of caps 530, 532 operativeto distribute reactants to the reactor microchannels take products awaythat exit the reactor microchannels. More specifically, each cap 530includes a circular, semi-cylindrical shape that is convex on theoutside and concave on the interior. The interior is in fluidcommunication with the inlet side of each of the reactor microchannelsof the modules 10 and receives reactants via a sealed fluid connectionwith an inlet pipe 536. After the reactants have been reacted within thereactor microchannels, the outlet from these microchannels is collectedin the second cap 532. Similar to the inlet cap 530, the outlet cap 532comprises a circular, semi-cylindrical shape that is convex on theoutside and concave on the interior. In order to outlet products fromthe outlet cap 532, an outlet pipe 538 is welded to the outlet cap tocreate a fluid tight seal therebetween and communication between theinterior of the outlet cap and the interior of the outlet pipe. Inparticular, each cap 530, 532 is welded circumferentially to therespective ring 502 in order to ensure a fluid tight seal between thecap and ring. In this manner, fluid entering or exiting the reactormicrochannels is not mixed with the coolant fluid.

Referencing FIG. 43, an exemplary tower 600 incorporates a plurality ofmicrochannel unit operations 500, with some minor modifications. Insteadof using circular band 518 to bound the rings 502, the tower makes useof a cylindrical housing 602 that includes a coolant vapor outlet 604 atthe top and a coolant liquid outlet 606 at the bottom. Similarly, thesame coolant inlet pipe 514 supplies coolant to each of the unitoperations 500. And the tower 600 also uses a common reactant inlet pipe536 for each of the unit operations 500, while a common product outletpipe 538 is similarly used for each of the unit operations. Otherwise,the components and operation of the unit operations remains unchanged.

Referring to FIG. 44, an exemplary schematic 700 shows how the exemplaryembodiments may be integrated with commercially available components toprovide a working FT plant. In exemplary form, one or more modules 10(see FIG. 1) may be incorporated into a microchannel unit operation 702.In exemplary form, the modules are FT reactor microchannels with coolantchannels interposing the reactor microchannels. These unit operations702 may be arranged in a bank 704 to comprise a plurality of unitoperations. Each bank 704 may be fabricated as a stand-alone assembly orincorporated into a larger microchannel assembly. In exemplary form, aplurality of banks 704 are fabricated and positioned on a readilyportable structure, such as a skid. This portable structure includes therequisite piping connections to receive at least one coolant inletstream, at least one coolant outlet stream, at least one FT reactantstream, and at least one FT product stream. In exemplary form, the FTproduct stream may be directed to a FT liquid-vapor separator 710 and/ora FT wax vapor-liquid separator 712. Each of these devices 710, 712 mayalso be connected to a respective FT wax condenser 714 and a FT liquidcondenser 716. In order to cool the coolant exiting the banks 704, theoutlet coolant stream may be directed by a coolant pump 720 through asteam drum 722 and thereafter returned to the inlet coolant side of thebanks. Obviously, the schematic does not include all of the requisitepiping, but is shown merely to show how the microchannel devicesdisclosed herein may be incorporated with commercially available processequipment to comprise a small footprint FT plant, with the same orgreater FT product output.

Referring to FIGS. 45-48 and 53, an exemplary microchannel reactor 800includes a plurality of cores 802, where each core 802 comprises aplurality of sub-stacks 804. Each sub-stack 804 comprises a plurality ofstacks 806 that are fabricated in accordance with the process previouslydescribed to fabricate the microchannel module device 10, which includeda plurality of microchannel coolant and reaction subassemblies 12, 14(with the exception that each exemplary reaction subassembly 812includes two waveforms 44 instead of the three waveforms described aspart of the previous reaction subassembly 14).

In exemplary form, each stack 806 comprises alternating microchannelcoolant and reaction subassemblies 810, 812 that are thirty layers thick(fifteen microchannel coolant subassemblies 810 and fifteen reactionsubassemblies 812). The edges of the subassemblies 810, 812 arechamfered to allow for perimeter welding to joint the subassemblies toone another. At the top and bottom of each stack 806, a metal spacersheet 814 is mounted thereto, having a thickness of approximately 0.125inches, to construct a sub-stack 804. Upon completion of each sub-stack804, the exemplary dimensions are 24.0 inches in length, 24.0 inches inwidth, and 5.0 inches in height.

A plurality of sub-stacks 804, in exemplary form eight sub-stacks, arestacked together so that the coolant subassembly's 810 inlets are allarranged on a single side, while the coolant subassembly's 810 outletsare all arranged on an opposite side. Similarly, the plurality ofsub-stacks 804 are stacked together so that the reaction subassembly's812 inlets are all arranged on a single side, while the reactionsubassembly's 812 outlets are all arranged on an opposite side. In thismanner, the direction of fluid flow into and out of each sub-stacks 804is the same, thereby making fluid distribution to the subassemblies 810,812 simplified. Each of the metal spacer sheets 814 is chamfered toprovide for peripheral welding of adjacent spacer sheets to join thesub-stacks 804 to one another to create the core 802. In this exemplaryembodiment, the core 802 has exemplary dimensions of 24.0 inches inlength, 24.0 inches in width, and 40.0 inches in height.

Referring to FIGS. 49 and 50, the exemplary core 802 is mounted to aseries of rectangular boundary supports 820, 822 having chamfered edgesand having lengths that are substantially the same dimension as thecore's thickness. In this embodiment, there are four coolant boundarysupports 820 each having a length of 40.0 inches, a width of 6.5 inchesand a thickness of 1.5 inches. There are also four reactant boundarysupports 822 each having a length of 40.0 inches, a width of 4.0 inchesand a thickness of 1.0 inches. Each of the four reactant boundarysupports 822 is vertically oriented along its length and positioned toextend perpendicularly away one of the reactant faces 824. Inparticular, the far edge of each reactant face 824 is welded along thelength of one side of a corresponding reactant boundary support 822. Inaddition, each of the four coolant boundary supports 820 is verticallyoriented along its length and positioned to extend perpendicularly awayfrom a corresponding reactant boundary support 822. More specifically, alengthwise end (not welded to the core 802) of each reactant boundarysupport 822 is welded to a lengthwise end of a corresponding coolantboundary support 820, thereby extending perpendicularly with respect toa respective coolant face 826. Corresponding top and bottom rectangularplates 830 are mounted to the respective flat top and bottom surfaces ofthe core 802 and oriented so that the lengthwise dimension of each plateoverlaps each reactant face 824 of the core by 4.0 inches and thewidthwise dimension overlaps each coolant face 824 the core by 6.5inches. Likewise, the respective ends of the rectangular boundarysupports 820, 822 are mounted to the rectangular plates 830 to create arectangular halo. In exemplary form, the reactant side rectangular halo832 has a dimension of 42.0 inches in length, 24.0 inches in width, and4.0 inches in height, while the coolant side rectangular halo 834 has adimension of 42.0 inches in length, 32.0 inches in width, and 4.0 inchesin height.

Referencing FIG. 51, each of the four reactant boundary supports 822includes a series of T-shaped vertical channels 840 that are spacedapart from one another along the length of each support. In exemplaryform, the channels 840 of complimentary reactant boundary supports 822are adapted to face one another along the interior perimeter of thereactant side halo 832 and be aligned with one another. As will bediscussed in more detail hereafter, each of these channels 840 isadapted to receive the end of a stainless steel bolt 856. The dimensionsof the T-shaped vertical channel 840 are chosen to allow for the headand shaft of the bolt 856 to be vertically repositionable, but inhibitthe head of the bolt from being rotated while received within thechannel. Beneath the T-shaped vertical channels 840, a lengthwiserectangular notch 844 is formed within each support 822. In exemplaryform, the notches 844 of complimentary reactant boundary supports 822are adapted to face one another and be aligned with one another alongthe interior perimeter of the reactant side halo 832. Likewise, the topand bottom plates 830 also include lengthwise rectangular notch 844along the interior perimeter of the reactant side halo 832.

As shown in FIG. 52, the rectangular notch 844 is sized tolongitudinally receive a catalyst screen 846 that is partially wrappedaround a hollow tube 848. In this exemplary embodiment, the screen 846comprises a stainless steel mesh having an average particle opening of0.023 inches (i.e., mesh size of 270×270, using 0.0014 diameter wire),while the tube 848 comprises 96 gauge (0.006 inches in wall thickness)copper pipe. In this manner, the diameter of the tube 848 and thethickness of the screen 846 are cooperate to occupy the widthwisedimension of the notch 844 so that when the tube (with the screen 846wrapped therearound) is inserted into the notch, a significant amount offorce is necessary to push the tube into the interior of the notch,thereby creating a friction fit to retain the screen generally taut inbetween opposed notches.

Referring to FIGS. 53-56, the exemplary microchannel reactor 800includes a pair of retention subassemblies 850 in order to retainparticulate catalyst within microchannels of the reaction subassemblies812. It should be noted that the retention subassemblies 850 are mirrorimages of one another, with one subassembly positioned on the inlet sideof the reaction subassemblies 812, while the second subassembly ispositioned on the outlet side of the reaction subassemblies 812.Accordingly, a discussion of only one of the subassemblies 850 will beprovided in furtherance of brevity.

In this exemplary embodiment, each retention subassembly 850 comprises ascreen 846, a rectangular tube 848 frame, four porous foam inserts 852,and four retention frames 854, along with corresponding fasteners 856 tosecure the frames to the reactant boundary supports 822. As discussedpreviously, the screen 846 is wrapped around the rectangular tube frame848 and inserted into the notches 844 along the interior perimeter ofthe reactant side halo 832.

After the screen 846 is installed, the four porous foam inserts 852 arelaid on top of the screen 846, adjacent one another, to cover the areaof the screen coming in contact with the particulate catalyst (notshown). It should be noted that greater than four foam inserts 852 orless than four foam inserts may be used so long as the area of thescreen 846 coming in contact with the particulate catalyst issubstantially covered. In this exemplary embodiment, each foam insert852 comprises foamed stainless steel having a pore size of 65 pours perlinear inch and a tolerance of 0.006 inches for the length, width, andthickness. The foam inserts 852 act as a support for the more easilydeformable screen 846.

In order to retain the inserts 852 in position, the exemplary retentionsubassemblies 850 include four retention frames 854 and correspondingfasteners 856 used to secure the retention frames to reactant boundarysupports 822. In exemplary form, there is provided a single retentionframe 854 for each foam insert 852, but it should be noted that thisratio is not required. In other words, multiple retention frames 854 maybe provided for a single foam insert 852 or a single retention frame maybe provided for multiple foam inserts. In this exemplary embodiment, theretention frames 854 are fabricated from stainless steel and comprise arectangular shape and a vertical stiffening rib 860. At the ends of therectangular frame 854 are a series of tabs 862 having longitudinal slotsto accommodate throughput of a threaded end of a bolt 856. Thislongitudinal slot provides vertical adjustability of the bolt 856 withrespect to the frame 854. In exemplary form, eight bolts andcorresponding nuts are used to mount each frame 854 to the opposingreactant boundary supports 822. More specifically, each bolt head 856 isinserted into a corresponding T-shaped vertical channel 840 of areactant boundary support 822 so that the threaded end of the boltextends through the longitudinal slot of the tab 862. Thereafter, theframe 854 is pushed flush against the foam insert 852 and the nut 856 istightened with respect to the bolt to retain the frame in this position.This process is repeated until each frame 854 is secured in position.

As will be discussed in more detail hereafter, catalyst housed withinthe reaction microchannels of the reaction subassemblies 812 may need tobe replaced or regenerated. In either instance, this will most likelyrequire removal of the catalyst from the reaction microchannels. Butbefore this can be accomplished, at least one of the retentionsubassemblies 850 (preferably both subassemblies) will need to beremoved to gain access to the catalyst. In order to remove eachsubassembly 850, one would follow the opposite process discussedpreviously for installing the subassembly. Namely, the frames 854 wouldbe removed, thereafter the foam inserts 852 would be removed, and thenthe screen 846 would be removed last, thus providing direct access tothe catalyst within the reactant microchannels.

Referencing FIGS. 57-63, multiple microchannel reactors 800 may bemounted to one another as part of a microchannel unit 870. The followingis a discussion describing how one may utilize multiple microchannelreactors 800 to fabricate a microchannel unit 870.

Referring to FIG. 57, three microchannel reactors 800 are positioned endto end and mounted to one another (shown without the retentionsubassemblies 850). In exemplary form, each microchannel reactorincludes four sides, with a first side comprising a reactant inlet side880, a second side (angled 90 degrees with respect to the first side)comprising a coolant inlet side 882, a third side (angled 90 degreeswith respect to the second side and 180 degrees with respect to thefirst side) comprising a product outlet side 884, and a fourth side(angled 90 degrees with respect to the third side and 90 degrees withrespect to the first side) comprising a coolant outlet side 886. And thefour sides are aligned so that when the microchannel reactors 800 aremounted to one another, all of the reactant inlets 880 are on the sameside, as are the coolant inlets 882, the product outlets 884, and thecoolant outlets 886. After aligning and mounting the microchannelreactors 800 to one another, circular end plates 890 are mounted to theexposed top and bottom of reactors. At this point, the configurationshown in FIG. 57 may follow a plurality of fabrication paths.

A first of these fabrication paths is documented in FIG. 58. Inexemplary form, the microchannel reactors 800 and circular end plates890 are inserted axially into a cylindrical shell 900 so that thelongitudinal ends of the shell are substantially flush with the circularend plates. This cylindrical shell 900 has a longitudinal, horizontalcircular cross-section and is pre-processed to include a series ofopenings 902, 904. A first of these openings 902 is repeated six timesand comprises a rather large circular opening. These openings 902 arelongitudinally spaced apart on opposing sides (three on each side) ofthe shell 900 in order to provide three openings to the reactant inletside 880 of the three microchannel reactors 800 and three opening to theproduct outlet side 884 of the microchannel reactors. A second of theseopenings 904 is repeated nine times and comprises a smaller circularopening. These openings 904 are longitudinally spaced apart on opposingsides of the shell 900 in order to provide three openings to the coolantinlet side 882 of the three microchannel reactors 800 and six opening tothe coolant outlet side 886 of the microchannel reactors. After theshell is properly positioned, as described above, the shell is mountedto the microchannel reactors 800 and circular end plates 890 so thatfluid entering the three openings 902 nearest the reactant inlet side880 is not in communication with either the coolant inlet side 882 orthe coolant outlet side 886. Similarly, fluid entering the threeopenings 904 nearest the coolant inlet side 882 is not in communicationwith either the reactant inlet side 880 or the product outlet side 884.Consequently, each of the four sides 880-886 is isolated from oneanother except communication existing within the microchannel reactors800. The completed assembly is shown in FIG. 61

A second of these fabrication paths is documented in FIGS. 59 and 60. Inexemplary form, corresponding side plates 920-926 are mounted to thereactant inlet side 880, the coolant inlet side 882, the product outletside 884, and the coolant outlet side 886. In particular, a first plate920 has an arcuate profile and includes three openings 928 providingaccess to the coolant inlet side 882 of the three microchannel reactors800. A second plate 922 also has an arcuate profile and includes sixopenings 930 providing access to the coolant outlet side 888 of thethree microchannel reactors 800. A third plate 924 also has an arcuateprofile and includes three larger openings 932 providing access to thereactant inlet side 880 of the three microchannel reactors 800. A fourthplate 926 also has an arcuate profile and includes three larger openings934 providing access to the product outlet side 884 of the threemicrochannel reactors 800. Each of the corresponding side plates 920-926is mounted to the microchannel reactors 800 and circular end plates 890so that fluid entering the three openings 932 nearest the reactant inletside 880 is not in communication with either the coolant inlet side 882or the coolant outlet side 886. Similarly, fluid entering the threeopenings 928 nearest the coolant inlet side 882 is not in communicationwith either the reactant inlet side 880 or the product outlet side 884.Consequently, each of the four sides 880-886 is isolated from oneanother except communication existing within the microchannel reactors800. The completed assembly is shown in FIG. 61 and is functionally thesame as the completed assembly using the cylindrical shell 900.

Referencing FIG. 61, six manways 940 are respectively mounted to the sixopenings providing direct access to the microchannel reactors 800reactant inlet side 880 and the product outlet side 884. In exemplaryform, the manways 940 are welded to the periphery of the openings andinclude access points that are large enough to provide meaningful accessto the reactant microchannels of each microchannel reactor.

Referring to FIG. 62, the resultant structure shown in FIG. 61 isreinforced at its ends by mounting a series of stiffening braces 950that are arranged to tie into one another and extend both vertically andside to side.

As shown in FIG. 63, the resultant structure of FIG. 62 has piping andassociated flanges 952 mounted to deliver coolant to the microchannelreactors and carry away coolant from the microchannel reactors. Inaddition, piping and associated flanges 954 are mounted to the resultantstructure of FIG. 62 to deliver reactant to the microchannel reactorsand carry away product from the microchannel reactors.

Referring to FIGS. 64-68, each exemplary microchannel unit 870 may needto have the reaction microchannels of the reaction subassemblies 812loaded with catalyst subsequent to assembly. In order to load catalystinto the reaction microchannels and dislodge spent catalyst from thereaction microchannels, the instant disclosure includes an ultrasonicdensification unit 1000. By way of example, the ultrasonic densificationunit 1000 is fabricated from component parts sized to allow insertion ofthe ultrasonic densification unit through one or more of the manways 940on the reaction inlet side. This compact densification unit 1000 solvesthe problem of access to ultrasonic technology in the field to service amicrochannel unit 870. More specifically, larger ultrasonic equipmentmay be used to initially pack catalyst, but this larger equipment is notfeasible for use in the field to load fresh catalyst by servicetechnicians and certainly not able to be inserted through a manwaycover.

By way of example and not limitation, the ultrasonic densification unit1000 can be assembled from multiple pre-assembled sections and installedin the interior of the microchannel unit 870. The microchannel unit isconstructed in order to be adapted to use the ultrasonic densificationunit. For example, the four reactant boundary supports 822 includes aseries of T-shaped vertical channels 840 that are adapted to receivefasteners from two right side rail sections, two left side railsections. In this example, five pre-assembled sections are used. Thesepreassembled sections comprise two right side rail sections, two leftside rail sections, and a carriage assembly. It should be noted that theultrasonic densification unit 1000 may be assembled from less than ormore than five pre-assembled sections.

Referencing FIG. 66, an exemplary microchannel unit 870 is shown withthe third plate 924 removed (see FIG. 60) and the first manway 940removed (see FIG. 61) for illustration purposes only in order to showthe installed position of the ultrasonic densification unit 1000 (withinthe microchannel unit 870) on the reactant inlet side 880 of a first ofthe three microchannel reactors 800. Prior to gaining access to thereactant inlet side 880, it may be necessary to remove the retentionsubassemblies 850 directly covering the top of the reactionsubassemblies 812. As will be discussed in more detail hereafter, thedensification unit 1000 includes a densification carriage assembly 1010that traverses along a pair of spaced apart rails 1020 in order tosubject the contents of a predetermined portion of the reactionsubassemblies 812 to ultrasonic waves in an incremental fashion untilall of the reaction subassemblies of a microchannel reactor 800 havebeen processed. In particular, each of the rails 1020 engagescorresponding reactant boundary supports 822 of the microchannel reactor800 to secure the densification unit 1000 to the microchannel reactor800.

Referring to FIGS. 67-69, the densification unit 1000 includes thedensification carriage assembly 1010 that comprises numerous components.All of the components of the carriage assembly 1010 are mounted to acarriage baseplate 1030. An underside of the carriage baseplate 1030includes four recesses that each accommodate a self-lubricated camfollower 1032. The underside also has mounted thereto a pair ofultrasonic horns 1034.

On the top surface of the carriage baseplate 1030 is mounted a pin block1040 proximate each end that is coupled to a pneumatic piston assembly1042. The piston assembly 1042 engages a shot pin 1044 that isrepositionable between an extended position and a retracted position. Aswill be discussed in more detail hereafter, when the shot pin 1044 is inits extended position and received within one of a plurality of orifices1046 of a respective rail 1020 the carriage assembly 1010 is notrepositionable with respect to the rails, while when the shot pin is inits retracted position the carriage assembly may be repositionable withrespect to the rails. In addition, a ball plunger 1048 is mounted withina recess that extends into the end of the carriage baseplate 1030. Thisball plunger 1048 is also repositionable between an extended positionand a retracted position, where the extended position has a portion ofthe ball plunger received within one of a plurality of orifices 1050 ofone of the rails 1020 the carriage assembly 1010 so that the carriageassembly is not repositionable with respect to the rails, while theretracted position withdrawals the ball plunger from the orifice so thatthe carriage assembly may be repositionable with respect to the rails.

Centered between the pneumatic piston assemblies 1042 is a booster mount1056 to which a pair of ultrasonic converters 1058 are mounted. In thisexemplary embodiment, each ultrasonic horn 1034 is coupled to arespective ultrasonic converter 1058. In order to secure the ultrasonicconverter 1058 in the desired position, both the booster mount 1056 anda booster mount cap 1060 includes a semicircular cut-out. In thismanner, once the booster mount cap 1060 is attached to the booster mount1056 using fasteners (e.g., bolts), the fasteners may be tightened to sothe booster mount and cap sandwich a respective ultrasonic converter1058. The booster mount 1056 also includes a depression that is sized toreceive a portion of a compact guide cylinder 1064. The guide cylinderperforms the function of raising and lowering the ultrasonic horns toprovide contact to and pressure against the reactor surface duringdensification and raising to allow for movement along the rail. On therear of the guide cylinder 1064 is mounted a bracket 1072 that sits uponthe top of the carriage baseplate 1030. The guide bracket provides anattachment point for the guide cylinder to hold it stable during raisingand lowering operation.

Each of the pair of spaced apart rails 1020 comprises separablecomponents to facilitate assembly inside the exemplary microchannel unit870 using one of the manways 940 as an egress location for thecomponents. In this exemplary embodiment, the rails 1020 each include atwo sections that are assembled to one another using a dovetail cut thatextends vertically through the side guides 1080, 1082. Each side guideis mounted to a respective angle section 1086, 1088 having an L-shapedninety degree profile. In this exemplary embodiment, a series of dowels1090 extend through the angle sections 1086, 1088 and are receivedwithin corresponding recesses formed into the bottom of the side guides1080, 1082 in order to mount the angle sections to the side guides.

As discussed briefly beforehand, each exemplary microchannel unit 870may need to have its reaction microchannels of the reactionsubassemblies 812 loaded with catalyst subsequent to assembly. In orderto load catalyst into the reaction microchannels one may start byremoving one of the manway 940 covers as well as the top retentionsubassembly 850 to expose the reaction microchannels of the reactionsubassemblies 812. After the reaction microchannels are exposed, one maydeliver particulate catalyst on top of the reaction microchannels, wherethe particulate catalyst is small enough in size to flow into thereaction microchannels. This process is carried out until almost all, ifnot all, of the reaction microchannels appear to be full of particulatecatalyst (i.e., the particulate catalyst comes to the top of thereaction microchannel). At this point, one may install the ultrasonicdensification unit 1000.

Installation of the ultrasonic densification unit 1000 includesassembling the rails 1020 and thereafter securing the rails to therespective reactant boundary supports 822 (see FIG. 51). Likewise, thedensification carriage assembly 1010 is brought through the open manway940 and installed onto the rails 1020 so that the cam followers 1032 situpon the horizontal surface of the angle sections 1086, 1088. It shouldbe noted that the rails 1020 are installed onto the reactant boundarysupports 822 so the ultrasonic horns 1034 will vertically overly and canbe vertically lowered to contact the microchannel unit. In this example,the ultrasonic horns contact a respective coolant subassembly 810interposing respective reactant subassemblies 812 when the shot pin 1044is in its extended position and received within one of a plurality oforifices 1046 of a respective side guides 1080, 1082. In exemplary form,the side guides 1080, 1082 each include thirty nine orifices 1046 thatcorrespond to a total of thirty nine coolant subassemblies 810interposing forty reactant subassemblies 812 (the actual numbers aredouble these figures because each horn 1034 overlies a different set ofsubassemblies).

Starting at orifice #1, the shot pins 1044 are moved to their extendedposition and received within orifice #1 1046. Thereafter, the horns 1034are lowered to contact and affirmatively pressed against the firstcoolant subassembly 810. The ultrasonic horns 1034 are then activatedfor a predetermined time (e.g., for ten seconds), which operates tocompact the catalyst within each of the adjacent reactant subassemblies812. Each of the horns 1034 is deactivated and raised, followed bymovement of the shot pins 1044 to their retracted position. Thereafter,the carriage assembly 1010 is repositioned so that the shot pins 1044are moved into axial alignment with orifice #2. The shot pins 1044 aremoved to their extended position, the horns 1034 lowered and activatedto compact catalyst within each of the adjacent reactant subassemblies812. This process is repeated until all reactant subassemblies 812 havebeen compacted. It is important to sequentially perform this process inorder to provide ultrasonic energy to different areas of the surface ofthe unit to achieve uniform packing. It should be noted that the controlof the carriage assembly 1010 and its components may be any combinationof manual or automatic manipulation.

After the first round of compaction, the reaction microchannels exhibitbetween six to eight inches of variation in catalyst packing. It ispreferred that the catalyst be uniformly packed throughout the reactionmicrochannels, so additional catalyst is added and substantially leveledover the microchannels. Thereafter, a second round of compaction usingthe ultrasonic densification unit 1000 is carried out that follows thesame sequence as discussed for the first round. After a second round ofcompaction, the reaction microchannels exhibit approximately one halfinch of variation in catalyst packing. A third catalyst addition step iscarried out, followed by a third round of compaction. This sequence ofcatalyst addition and compaction may be repeated as many times asnecessary to achieve the desired catalyst densification within thereaction microchannels of the reactant subassemblies 812. When thedesired densification is reacted, the ultrasonic densification unit 1000is disassembled and removed from the microchannel unit 870 via the firstmanway 940. Thereafter, the retention subassembly 850 directly coveringthe top of the reaction subassemblies 812 is installed, followed by themanway 940 cover.

It is also within the scope of the disclosure to utilize the ultrasonicdensification unit 1000 to help with removal of spent catalyst from thereactant subassemblies 812. This exemplary sequence is particularlyuseful for field servicing of the microchannel unit 870 after it hasbeen permanently installed and operating, but needs to have the spentcatalyst regenerated or replaced. An exemplary sequence begins byremoving both the top and bottom manway 940 covers for the exemplarymicrochannel unit 870. Thereafter, both the top and bottom the retentionsubassemblies 850 directly covering the top and bottom of the reactionsubassemblies 812 are removed. The components of the densification unit1000 are then inserted through the top manway 940 and assembled so thatthe rails are fastened to a respective angle section 1086, 1088 and thecarriage assembly 1020 can ride upon the rails 1020.

Starting at orifice #1, the shot pins 1044 are moved to their extendedposition and received within orifice #1 1046. Thereafter, the horns 1034are lowered to contact the first coolant subassembly 810. The ultrasonichorns 1034 are then activated for a predetermined time (e.g., for tenseconds), which operates to dislodge caked catalyst from the interior ofthe reactant subassemblies 812. The dislodged catalyst falls out of thebottom of the reactant microchannels and is collected and removed viathe bottom manway. Each of the horns 1034 is deactivated and raised,followed by movement of the shot pins 1044 to their retracted position.Thereafter, the carriage assembly 1010 is repositioned so that the shotpins 1044 are moved into axial alignment with orifice #2. The shot pins1044 are moved to their extended position, the horns 1034 lowered andactivated to dislodge further catalyst from within each of the adjacentreactant subassemblies 812. This process is repeated until all orsubstantially all of the catalyst has been dislodged from the reactantsubassemblies 812. As discussed above, the movement sequence of thecarriage assembly 1020 components may be any combination of manual orautomatic manipulation.

After a first round of catalyst dislodgement is performed, the reactionmicrochannels may be optionally washed or rinsed with a fluid to removeany residual catalyst. It should be noted that this washing process isoptional and need not be performed in all instances prior to loading newcatalyst to the microchannel reaction subassemblies 812. After the spentcatalyst is collected, the retention subassembly 850 is installed at thebottom of the reaction subassemblies 812 and the bottom manway coverreattached. Thereafter, new or refurbished catalyst is added to the topof the reaction subassemblies and subjected to a densification processto properly pack catalyst within the reaction subassemblies 812. Adetailed sequence of the densification process has been omitted infurtherance of brevity given that it is generally the same sequence asdiscussed above for loading new catalyst to the reaction subassemblies.

To overcome challenges of propagating ultrasound waves through the wallsof a microchannel reactor body, the ultrasonic source horn (Ultra SonicSeal, Model ST, 1500 watt ultrasound power supply (Broomall, Pa.) isequipped with a 2.54 cm×20.3 cm titanium horn manufactured by ToolTex,Inc. Grove City, Ohio.

It was demonstrated that if the horn is positioned in the mannerdescribed above, the reactant microchannels (that contain theparticulate catalyst) function as a focusing medium for the ultrasonicenergy by creating transversal waves that transmit ultrasound vibrationthrough the walls of the channels in a longitudinal direction. Thisproved effective in transmitting the vibration frequency through theentire length of the microchannels (up to 61 cm in length demonstratedand at least 1 m or more in length expected) channels with minimalattenuation. In this case the ultrasound components consisted of a 1500W supply transformer, an amplitude booster and a tuned titaniumultrasonic horn measuring 20.3 cm long by 2.54 cm wide. The position ofthe ultrasound unit was pneumatically adjustable in the vertical planealong the length of the steel column. The pneumatic control alsopositioned the horn directly on the top edge of the channels withadjustability of its contact pressure against the surface of the device.Either a metal screen or thin metal plate was placed between the top ofthe channels and the emitting horn to prevent contact damage to the endsof the reactant microchannels. It is envisioned that this approach willalso work for stainless steel microchannels with or without using awaveform. It is not believed that that the material of the microchannelis critical to operation of this method, although metals are preferred.

Ultrasound densification testing was conducted on particulate materialpacked between a steel and acrylic plate test device. Ultrasound wastransmitted through a steel plate or from the top of the device at theapex of the channels. Adjustments were made to burst duration andcontact pressure of the horn against the device during these initialtrials. Burst duration was typically from 5-20 seconds and the horn wasadjusted to a frequency of 20 kHz at amplitude 0.5 mm. Pressure of thehorn against the device body was surprisingly found to be an importantparameter. If the pressure of the horn was too low it hammered againstthe contact surface at its input frequency increasing the potential fordamage to the face of the horn with little propagation of ultrasoundinto the device. If the pressure was too high the horn “coupled” withthe device and sonic energy was mitigated, diminishing the efficiency ofthe process.

Densification was more than ten times faster and beyond that which wasachieved through mechanical means. For example, a 61 cm long waveformwas filled with particles with an average diameter of 300 μm supportmaterial and densified by striking the device body with a rubber mallet˜400 times over a 10 minute period until perceived maximum densificationwas achieved. Introduction of ultrasound through the tops of thechannels for a period of only 5 seconds settled the powder bed anotherinch. Fill level uniformity across all channels also improved comparedto mechanical vibration. In this case the contact pressure of the hornagainst the channels was 25 psi. In a demonstration of excessive energyinput the contact pressure was increased to 45 psi and the powder withinthe channels was disrupted through fluidization resulting ininconsistent density and poor fill level uniformity.

Following from the above description and invention summaries, it shouldbe apparent to those of ordinary skill in the art that, while themethods and apparatuses herein described constitute exemplaryembodiments of the present invention, the invention contained herein isnot limited to this precise embodiment and that changes may be made tosuch embodiments without departing from the scope of the invention asdefined by the claims. Additionally, it is to be understood that theinvention is defined by the claims and it is not intended that anylimitations or elements describing the exemplary embodiments set forthherein are to be incorporated into the interpretation of any claimelement unless such limitation or element is explicitly stated.Likewise, it is to be understood that it is not necessary to meet any orall of the identified advantages or objects of the invention disclosedherein in order to fall within the scope of any claims, since theinvention is defined by the claims and since inherent and/or unforeseenadvantages of the present invention may exist even though they may nothave been explicitly discussed herein.

What is claimed is: 1-78. (canceled)
 79. A microchannel device,comprising: a plurality of parallel arrays of microchannel coolantchannels; a plurality of reaction microchannels alternating in acircular arrangement with the plurality of parallel arrays of coolantchannels to surround an axial core; wherein the microchannel coolantchannels extend perpendicularly to the central axis of the axial core;and wherein the reaction microchannels extend in a direction that isparallel to the axis of the axial core and perpendicularly to the arraysof microchannel coolant channels.
 80. The microchannel device of claim79 wherein the reaction microchannels comprise a waveform.
 81. Themicrochannel device of claim 79 wherein the reaction microchannelscomprise catalyst.
 82. The microchannel device of claim 79 wherein thereaction microchannels comprise a fixed bed Fischer-Tropsch catalyst.83. The microchannel device of claim 79 having a circular cross-sectionin a plane perpendicular to the central axis of the axial core.
 84. Themicrochannel device of claim 79 wherein the reaction microchannels havea wedge shape with the thin edge of the each wedge nearest the axialcore.
 85. The microchannel device of claim 84 wherein the reactionmicrochannels comprise a waveform having an amplitude that increases asthe distance from the central axis increases.
 86. The microchanneldevice of claim 79 comprising a first reaction manifold having a ringshape that connects with inlets of the reaction microchannels.
 87. Themicrochannel device of claim 86 comprising a second reaction manifoldhaving a ring shape that connects with outlets of the reactionmicrochannels.
 88. The microchannel device of claim 79 comprising acoolant manifold in the axial core connected to inlets of the pluralityof parallel arrays of microchannel coolant channels.
 89. Themicrochannel device of claim 88 comprising a coolant manifold having aring-shaped manifold surrounding the plurality of reaction microchannelsalternating in a circular arrangement with the plurality of parallelarrays of coolant channels, and connected to outlets of the plurality ofparallel arrays of microchannel coolant channels.
 90. The microchanneldevice of claim 80 wherein the reaction microchannels comprise aFischer-Tropsch catalyst.
 91. A method of conducting a reaction in thedevice of claim 79, comprising: passing a coolant into the axial coreand then into the plurality of parallel arrays of microchannel coolantchannels; and passing a reactant stream into the plurality of reactionmicrochannels.
 92. The method of claim 91 wherein the reactant streamcomprises CO and H₂ and wherein a Fischer-Tropsch reaction occurs in theplurality of reaction microchannels.
 93. The method of claim 91 whereinthe coolant in the axial core flows parallel to the and the reactantstream in the reaction microchannels.
 94. A reactor assembly,comprising: microchannel coolant subassembly plates and reactorsubassembly plates that alternate in a circular arrangement to form anaxial core configured to provide for flow in a vertical direction;wherein the coolant subassembly plates comprise microchannels that areconnected to the axial core and extend in a horizontal direction awayfrom the core; and wherein the reactor subassembly plates comprisemicrochannels that extend in a vertical direction that is parallel tothe axial core.
 95. A method of conducting a unit operation in thereactor assembly of claim 94, comprising: passing a coolant into theaxial core and through the microchannels in the coolant subassemblyplates; passing a reactant steam through the microchannels in thesubassembly plates.